public class BigDecimal extends Number implements Comparable<BigDecimal>
BigDecimal
consists of an arbitrary precision
integer unscaled value and a 32bit integer scale. If zero or positive, the scale is the number of
digits to the right of the decimal point. If negative, the unscaled value of the number is multiplied by ten to the
power of the negation of the scale. The value of the number represented by the BigDecimal
is therefore
(unscaledValue × 10^{scale}).
The BigDecimal
class provides operations for arithmetic, scale manipulation, rounding, comparison, hashing,
and format conversion. The toString()
method provides a canonical representation of a BigDecimal
.
The BigDecimal
class gives its user complete control over rounding behavior. If no rounding mode is specified
and the exact result cannot be represented, an exception is thrown; otherwise, calculations can be carried out to a
chosen precision and rounding mode by supplying an appropriate MathContext
object to the operation. In either
case, eight rounding modes are provided for the control of rounding. Using the integer fields in this class
(such as ROUND_HALF_UP
) to represent rounding mode is largely obsolete; the enumeration values of the
RoundingMode
enum
, (such as RoundingMode.HALF_UP
) should be used instead.
When a MathContext
object is supplied with a precision setting of 0 (for example,
MathContext.UNLIMITED
), arithmetic operations are exact, as are the arithmetic methods which take no
MathContext
object. (This is the only behavior that was supported in releases prior to 5.) As a corollary of
computing the exact result, the rounding mode setting of a MathContext
object with a precision setting of 0
is not used and thus irrelevant. In the case of divide, the exact quotient could have an infinitely long decimal
expansion; for example, 1 divided by 3. If the quotient has a nonterminating decimal expansion and the operation is
specified to return an exact result, an ArithmeticException
is thrown. Otherwise, the exact result of the
division is returned, as done for other operations.
When the precision setting is not 0, the rules of BigDecimal
arithmetic are broadly compatible with selected
modes of operation of the arithmetic defined in ANSI X3.2741996 and ANSI X3.2741996/AM 12000 (section 7.4). Unlike
those standards, BigDecimal
includes many rounding modes, which were mandatory for division in
BigDecimal
releases prior to 5. Any conflicts between these ANSI standards and the BigDecimal
specification are resolved in favor of BigDecimal
.
Since the same numerical value can have different representations (with different scales), the rules of arithmetic and rounding must specify both the numerical result and the scale used in the result's representation.
In general the rounding modes and precision setting determine how operations return results with a limited number of
digits when the exact result has more digits (perhaps infinitely many in the case of division) than the number of
digits returned.
First, the total number of digits to return is specified by the MathContext
's precision
setting; this
determines the result's precision. The digit count starts from the leftmost nonzero digit of the exact result.
The rounding mode determines how any discarded trailing digits affect the returned result.
For all arithmetic operators , the operation is carried out as though an exact intermediate result were first calculated and then rounded to the number of digits specified by the precision setting (if necessary), using the selected rounding mode. If the exact result is not returned, some digit positions of the exact result are discarded. When rounding increases the magnitude of the returned result, it is possible for a new digit position to be created by a carry propagating to a leading "9" digit. For example, rounding the value 999.9 to three digits rounding up would be numerically equal to one thousand, represented as 100×10^{1}. In such cases, the new "1" is the leading digit position of the returned result.
Besides a logical exact result, each arithmetic operation has a preferred scale for representing a result. The preferred scale for each operation is listed in the table below.
Operation  Preferred Scale of Result 

Add  max(addend.scale(), augend.scale()) 
Subtract  max(minuend.scale(), subtrahend.scale()) 
Multiply  multiplier.scale() + multiplicand.scale() 
Divide  dividend.scale()  divisor.scale() 
1/32
is 0.03125
.
Before rounding, the scale of the logical exact intermediate result is the preferred scale for that operation. If the
exact numerical result cannot be represented in precision
digits, rounding selects the set of digits to
return and the scale of the result is reduced from the scale of the intermediate result to the least scale which can
represent the precision
digits actually returned. If the exact result can be represented with at most
precision
digits, the representation of the result with the scale closest to the preferred scale is returned.
In particular, an exactly representable quotient may be represented in fewer than precision
digits by
removing trailing zeros and decreasing the scale. For example, rounding to three digits using the
floor rounding mode,
19/100 = 0.19 // integer=19, scale=2
but
21/110 = 0.190 // integer=190, scale=3
Note that for add, subtract, and multiply, the reduction in scale will equal the number of digit positions of the exact result which are discarded. If the rounding causes a carry propagation to create a new highorder digit position, an additional digit of the result is discarded than when no new digit position is created.
Other methods may have slightly different rounding semantics. For example, the result of the pow
method using
the specified algorithm can occasionally differ from the rounded mathematical
result by more than one unit in the last place, one ulp.
Two types of operations are provided for manipulating the scale of a BigDecimal
: scaling/rounding operations
and decimal point motion operations. Scaling/rounding operations (setScale
and round
) return a BigDecimal
whose value is approximately (or exactly) equal to that of the operand, but whose scale
or precision is the specified value; that is, they increase or decrease the precision of the stored number with
minimal effect on its value. Decimal point motion operations (movePointLeft
and
movePointRight
) return a BigDecimal
created from the operand by moving the decimal
point a specified distance in the specified direction.
For the sake of brevity and clarity, pseudocode is used throughout the descriptions of BigDecimal
methods.
The pseudocode expression (i + j)
is shorthand for "a BigDecimal
whose value is that of the
BigDecimal
i
added to that of the BigDecimal
j
." The pseudocode expression
(i == j)
is shorthand for "true
if and only if the BigDecimal
i
represents the same
value as the BigDecimal
j
." Other pseudocode expressions are interpreted similarly. Square brackets
are used to represent the particular BigInteger
and scale pair defining a BigDecimal
value; for
example [19, 2] is the BigDecimal
numerically equal to 0.19 having a scale of 2.
Note: care should be exercised if BigDecimal
objects are used as keys in a SortedMap
or elements in a SortedSet
since BigDecimal
's natural ordering
is inconsistent with equals. See Comparable
, SortedMap
or
SortedSet
for more information.
All methods and constructors for this class throw NullPointerException
when passed a null
object
reference for any input parameter.
BigInteger
,
MathContext
,
RoundingMode
,
SortedMap
,
SortedSet
,
Serialized FormModifier and Type  Field and Description 

static BigDecimal 
ONE
The value 1, with a scale of 0.

static int 
ROUND_CEILING
Rounding mode to round towards positive infinity.

static int 
ROUND_DOWN
Rounding mode to round towards zero.

static int 
ROUND_FLOOR
Rounding mode to round towards negative infinity.

static int 
ROUND_HALF_DOWN
Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case
round down.

static int 
ROUND_HALF_EVEN
Rounding mode to round towards the "nearest neighbor" unless both neighbors are equidistant, in which
case, round towards the even neighbor.

static int 
ROUND_HALF_UP
Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case
round up.

static int 
ROUND_UNNECESSARY
Rounding mode to assert that the requested operation has an exact result, hence no rounding is necessary.

static int 
ROUND_UP
Rounding mode to round away from zero.

static BigDecimal 
TEN
The value 10, with a scale of 0.

static BigDecimal 
ZERO
The value 0, with a scale of 0.

Constructor and Description 

BigDecimal(BigInteger val)
Translates a
BigInteger into a BigDecimal . 
BigDecimal(BigInteger unscaledVal,
int scale)
Translates a
BigInteger unscaled value and an int scale into a BigDecimal . 
BigDecimal(BigInteger unscaledVal,
int scale,
MathContext mc)
Translates a
BigInteger unscaled value and an int scale into a BigDecimal , with rounding
according to the context settings. 
BigDecimal(BigInteger val,
MathContext mc)
Translates a
BigInteger into a BigDecimal rounding according to the context settings. 
BigDecimal(char[] in)
Translates a character array representation of a
BigDecimal into a BigDecimal , accepting the same
sequence of characters as the BigDecimal(String) constructor. 
BigDecimal(char[] in,
int offset,
int len)
Translates a character array representation of a
BigDecimal into a BigDecimal , accepting the same
sequence of characters as the BigDecimal(String) constructor, while allowing a subarray to be
specified. 
BigDecimal(char[] in,
int offset,
int len,
MathContext mc)
Translates a character array representation of a
BigDecimal into a BigDecimal , accepting the same
sequence of characters as the BigDecimal(String) constructor, while allowing a subarray to be specified
and with rounding according to the context settings. 
BigDecimal(char[] in,
MathContext mc)
Translates a character array representation of a
BigDecimal into a BigDecimal , accepting the same
sequence of characters as the BigDecimal(String) constructor and with rounding according to the context
settings. 
BigDecimal(double val)
Translates a
double into a BigDecimal which is the exact decimal representation of the
double 's binary floatingpoint value. 
BigDecimal(double val,
MathContext mc)
Translates a
double into a BigDecimal , with rounding according to the context settings. 
BigDecimal(int val)
Translates an
int into a BigDecimal . 
BigDecimal(int val,
MathContext mc)
Translates an
int into a BigDecimal , with rounding according to the context settings. 
BigDecimal(long val)
Translates a
long into a BigDecimal . 
BigDecimal(long val,
MathContext mc)
Translates a
long into a BigDecimal , with rounding according to the context settings. 
BigDecimal(String val)
Translates the string representation of a
BigDecimal into a BigDecimal . 
BigDecimal(String val,
MathContext mc)
Translates the string representation of a
BigDecimal into a BigDecimal , accepting the same
strings as the BigDecimal(String) constructor, with rounding according to the context settings. 
Modifier and Type  Method and Description 

BigDecimal 
abs()
Returns a
BigDecimal whose value is the absolute value of this BigDecimal , and whose scale is
this.scale() . 
BigDecimal 
abs(MathContext mc)
Returns a
BigDecimal whose value is the absolute value of this BigDecimal , with rounding
according to the context settings. 
BigDecimal 
add(BigDecimal augend)
Returns a
BigDecimal whose value is (this +
augend) , and whose scale is max(this.scale(),
augend.scale()) . 
BigDecimal 
add(BigDecimal augend,
MathContext mc)
Returns a
BigDecimal whose value is (this + augend) , with rounding according to the context
settings. 
byte 
byteValueExact()
Converts this
BigDecimal to a byte , checking for lost information. 
int 
compareTo(BigDecimal val)
Compares this
BigDecimal with the specified BigDecimal . 
BigDecimal 
divide(BigDecimal divisor)
Returns a
BigDecimal whose value is (this /
divisor) , and whose preferred scale is (this.scale() 
divisor.scale()) ; if the exact quotient cannot be represented (because it has a nonterminating decimal
expansion) an ArithmeticException is thrown. 
BigDecimal 
divide(BigDecimal divisor,
int roundingMode)
Returns a
BigDecimal whose value is (this /
divisor) , and whose scale is this.scale() . 
BigDecimal 
divide(BigDecimal divisor,
int scale,
int roundingMode)
Returns a
BigDecimal whose value is (this /
divisor) , and whose scale is as specified. 
BigDecimal 
divide(BigDecimal divisor,
int scale,
RoundingMode roundingMode)
Returns a
BigDecimal whose value is (this /
divisor) , and whose scale is as specified. 
BigDecimal 
divide(BigDecimal divisor,
MathContext mc)
Returns a
BigDecimal whose value is (this /
divisor) , with rounding according to the context settings. 
BigDecimal 
divide(BigDecimal divisor,
RoundingMode roundingMode)
Returns a
BigDecimal whose value is (this /
divisor) , and whose scale is this.scale() . 
BigDecimal[] 
divideAndRemainder(BigDecimal divisor)
Returns a twoelement
BigDecimal array containing the result of divideToIntegralValue followed by
the result of remainder on the two operands. 
BigDecimal[] 
divideAndRemainder(BigDecimal divisor,
MathContext mc)
Returns a twoelement
BigDecimal array containing the result of divideToIntegralValue followed by
the result of remainder on the two operands calculated with rounding according to the context settings. 
BigDecimal 
divideToIntegralValue(BigDecimal divisor)
Returns a
BigDecimal whose value is the integer part of the quotient (this / divisor) rounded
down. 
BigDecimal 
divideToIntegralValue(BigDecimal divisor,
MathContext mc)
Returns a
BigDecimal whose value is the integer part of (this / divisor) . 
double 
doubleValue()
Converts this
BigDecimal to a double . 
boolean 
equals(Object x)
Compares this
BigDecimal with the specified Object for equality. 
float 
floatValue()
Converts this
BigDecimal to a float . 
int 
hashCode()
Returns the hash code for this
BigDecimal . 
int 
intValue()
Converts this
BigDecimal to an int . 
int 
intValueExact()
Converts this
BigDecimal to an int , checking for lost information. 
long 
longValue()
Converts this
BigDecimal to a long . 
long 
longValueExact()
Converts this
BigDecimal to a long , checking for lost information. 
BigDecimal 
max(BigDecimal val)
Returns the maximum of this
BigDecimal and val . 
BigDecimal 
min(BigDecimal val)
Returns the minimum of this
BigDecimal and val . 
BigDecimal 
movePointLeft(int n)
Returns a
BigDecimal which is equivalent to this one with the decimal point moved n places to the
left. 
BigDecimal 
movePointRight(int n)
Returns a
BigDecimal which is equivalent to this one with the decimal point moved n places to the
right. 
BigDecimal 
multiply(BigDecimal multiplicand)
Returns a
BigDecimal whose value is (this ×
multiplicand), and whose scale is (this.scale() +
multiplicand.scale()) . 
BigDecimal 
multiply(BigDecimal multiplicand,
MathContext mc)
Returns a
BigDecimal whose value is (this ×
multiplicand), with rounding according to the context settings. 
BigDecimal 
negate()
Returns a
BigDecimal whose value is (this) , and whose scale is this.scale() . 
BigDecimal 
negate(MathContext mc)
Returns a
BigDecimal whose value is (this) , with rounding according to the context settings. 
BigDecimal 
plus()
Returns a
BigDecimal whose value is (+this) , and whose scale is this.scale() . 
BigDecimal 
plus(MathContext mc)
Returns a
BigDecimal whose value is (+this) , with rounding according to the context settings. 
BigDecimal 
pow(int n)
Returns a
BigDecimal whose value is (this^{n}), The power is computed exactly, to
unlimited precision. 
BigDecimal 
pow(int n,
MathContext mc)
Returns a
BigDecimal whose value is (this^{n}). 
int 
precision()
Returns the precision of this
BigDecimal . 
BigDecimal 
remainder(BigDecimal divisor)
Returns a
BigDecimal whose value is (this % divisor) . 
BigDecimal 
remainder(BigDecimal divisor,
MathContext mc)
Returns a
BigDecimal whose value is (this %
divisor) , with rounding according to the context settings. 
BigDecimal 
round(MathContext mc)
Returns a
BigDecimal rounded according to the MathContext settings. 
int 
scale()
Returns the scale of this
BigDecimal . 
BigDecimal 
scaleByPowerOfTen(int n)
Returns a BigDecimal whose numerical value is equal to (
this * 10^{n}). 
BigDecimal 
setScale(int newScale)
Returns a
BigDecimal whose scale is the specified value, and whose value is numerically equal to this
BigDecimal 's. 
BigDecimal 
setScale(int newScale,
int roundingMode)
Returns a
BigDecimal whose scale is the specified value, and whose unscaled value is determined by
multiplying or dividing this BigDecimal 's unscaled value by the appropriate power of ten to maintain its
overall value. 
BigDecimal 
setScale(int newScale,
RoundingMode roundingMode)
Returns a
BigDecimal whose scale is the specified value, and whose unscaled value is determined by
multiplying or dividing this BigDecimal 's unscaled value by the appropriate power of ten to maintain its
overall value. 
short 
shortValueExact()
Converts this
BigDecimal to a short , checking for lost information. 
int 
signum()
Returns the signum function of this
BigDecimal . 
BigDecimal 
stripTrailingZeros()
Returns a
BigDecimal which is numerically equal to this one but with any trailing zeros removed from the
representation. 
BigDecimal 
subtract(BigDecimal subtrahend)
Returns a
BigDecimal whose value is (this 
subtrahend) , and whose scale is max(this.scale(),
subtrahend.scale()) . 
BigDecimal 
subtract(BigDecimal subtrahend,
MathContext mc)
Returns a
BigDecimal whose value is (this  subtrahend) , with rounding according to the context
settings. 
BigInteger 
toBigInteger()
Converts this
BigDecimal to a BigInteger . 
BigInteger 
toBigIntegerExact()
Converts this
BigDecimal to a BigInteger , checking for lost information. 
String 
toEngineeringString()
Returns a string representation of this
BigDecimal , using engineering notation if an exponent is needed. 
String 
toPlainString()
Returns a string representation of this
BigDecimal without an exponent field. 
String 
toString()
Returns the string representation of this
BigDecimal , using scientific notation if an exponent is needed. 
BigDecimal 
ulp()
Returns the size of an ulp, a unit in the last place, of this
BigDecimal . 
BigInteger 
unscaledValue()
Returns a
BigInteger whose value is the unscaled value of this BigDecimal . 
static BigDecimal 
valueOf(double val)
Translates a
double into a BigDecimal , using the double 's canonical string representation
provided by the Double.toString(double) method. 
static BigDecimal 
valueOf(long val)
Translates a
long value into a BigDecimal with a scale of zero. 
static BigDecimal 
valueOf(long unscaledVal,
int scale)
Translates a
long unscaled value and an int scale into a BigDecimal . 
byteValue, shortValue
public static final BigDecimal ONE
public static final int ROUND_CEILING
BigDecimal
is positive, behaves as for
ROUND_UP
; if negative, behaves as for ROUND_DOWN
. Note that this rounding mode never decreases
the calculated value.public static final int ROUND_DOWN
public static final int ROUND_FLOOR
BigDecimal
is positive, behave as for
ROUND_DOWN
; if negative, behave as for ROUND_UP
. Note that this rounding mode never increases the
calculated value.public static final int ROUND_HALF_DOWN
ROUND_UP
if the discarded fraction is > 0.5; otherwise, behaves as
for ROUND_DOWN
.public static final int ROUND_HALF_EVEN
ROUND_HALF_UP
if the digit to the left of the
discarded fraction is odd; behaves as for ROUND_HALF_DOWN
if it's even. Note that this is the rounding
mode that minimizes cumulative error when applied repeatedly over a sequence of calculations.public static final int ROUND_HALF_UP
ROUND_UP
if the discarded fraction is ≥ 0.5; otherwise, behaves as for
ROUND_DOWN
. Note that this is the rounding mode that most of us were taught in grade school.public static final int ROUND_UNNECESSARY
ArithmeticException
is
thrown.public static final int ROUND_UP
public static final BigDecimal TEN
public static final BigDecimal ZERO
public BigDecimal(BigInteger val)
BigInteger
into a BigDecimal
. The scale of the BigDecimal
is zero.val
 BigInteger
value to be converted to BigDecimal
.public BigDecimal(BigInteger unscaledVal, int scale)
BigInteger
unscaled value and an int
scale into a BigDecimal
. The value of
the BigDecimal
is (unscaledVal × 10^{scale}).unscaledVal
 unscaled value of the BigDecimal
.scale
 scale of the BigDecimal
.public BigDecimal(BigInteger unscaledVal, int scale, MathContext mc)
BigInteger
unscaled value and an int
scale into a BigDecimal
, with rounding
according to the context settings. The value of the BigDecimal
is (unscaledVal ×
10^{scale}), rounded according to the precision
and rounding mode settings.unscaledVal
 unscaled value of the BigDecimal
.scale
 scale of the BigDecimal
.mc
 the context to use.ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
.public BigDecimal(BigInteger val, MathContext mc)
BigInteger
into a BigDecimal
rounding according to the context settings. The scale
of the BigDecimal
is zero.val
 BigInteger
value to be converted to BigDecimal
.mc
 the context to use.ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
.public BigDecimal(char[] in)
BigDecimal
into a BigDecimal
, accepting the same
sequence of characters as the BigDecimal(String)
constructor.
Note that if the sequence of characters is already available as a character array, using this constructor is
faster than converting the char
array to string and using the BigDecimal(String)
constructor .
in
 char
array that is the source of characters.NumberFormatException
 if in
is not a valid representation of a BigDecimal
.public BigDecimal(char[] in, int offset, int len)
BigDecimal
into a BigDecimal
, accepting the same
sequence of characters as the BigDecimal(String)
constructor, while allowing a subarray to be
specified.
Note that if the sequence of characters is already available within a character array, using this constructor is
faster than converting the char
array to string and using the BigDecimal(String)
constructor .
in
 char
array that is the source of characters.offset
 first character in the array to inspect.len
 number of characters to consider.NumberFormatException
 if in
is not a valid representation of a BigDecimal
or the defined subarray is not
wholly within in
.public BigDecimal(char[] in, int offset, int len, MathContext mc)
BigDecimal
into a BigDecimal
, accepting the same
sequence of characters as the BigDecimal(String)
constructor, while allowing a subarray to be specified
and with rounding according to the context settings.
Note that if the sequence of characters is already available within a character array, using this constructor is
faster than converting the char
array to string and using the BigDecimal(String)
constructor .
in
 char
array that is the source of characters.offset
 first character in the array to inspect.len
 number of characters to consider..mc
 the context to use.ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
.NumberFormatException
 if in
is not a valid representation of a BigDecimal
or the defined subarray is not
wholly within in
.public BigDecimal(char[] in, MathContext mc)
BigDecimal
into a BigDecimal
, accepting the same
sequence of characters as the BigDecimal(String)
constructor and with rounding according to the context
settings.
Note that if the sequence of characters is already available as a character array, using this constructor is
faster than converting the char
array to string and using the BigDecimal(String)
constructor .
in
 char
array that is the source of characters.mc
 the context to use.ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
.NumberFormatException
 if in
is not a valid representation of a BigDecimal
.public BigDecimal(double val)
double
into a BigDecimal
which is the exact decimal representation of the
double
's binary floatingpoint value. The scale of the returned BigDecimal
is the smallest value
such that (10^{scale} × val) is an integer.
Notes:
new BigDecimal(0.1)
in Java creates a BigDecimal
which is exactly equal to 0.1 (an unscaled value
of 1, with a scale of 1), but it is actually equal to 0.1000000000000000055511151231257827021181583404541015625.
This is because 0.1 cannot be represented exactly as a double
(or, for that matter, as a binary fraction
of any finite length). Thus, the value that is being passed in to the constructor is not exactly equal to
0.1, appearances notwithstanding.
String
constructor, on the other hand, is perfectly predictable: writing
new BigDecimal("0.1")
creates a BigDecimal
which is exactly equal to 0.1, as one would
expect. Therefore, it is generally recommended that the String
constructor be used in preference to this one.
double
must be used as a source for a BigDecimal
, note that this constructor provides
an exact conversion; it does not give the same result as converting the double
to a String
using
the Double.toString(double)
method and then using the BigDecimal(String)
constructor. To get
that result, use the static
valueOf(double)
method.
val
 double
value to be converted to BigDecimal
.NumberFormatException
 if val
is infinite or NaN.public BigDecimal(double val, MathContext mc)
double
into a BigDecimal
, with rounding according to the context settings. The scale
of the BigDecimal
is the smallest value such that (10^{scale} × val) is an
integer.
The results of this constructor can be somewhat unpredictable and its use is generally not recommended; see the
notes under the BigDecimal(double)
constructor.
val
 double
value to be converted to BigDecimal
.mc
 the context to use.ArithmeticException
 if the result is inexact but the RoundingMode is UNNECESSARY.NumberFormatException
 if val
is infinite or NaN.public BigDecimal(int val)
int
into a BigDecimal
. The scale of the BigDecimal
is zero.val
 int
value to be converted to BigDecimal
.public BigDecimal(int val, MathContext mc)
int
into a BigDecimal
, with rounding according to the context settings. The scale
of the BigDecimal
, before any rounding, is zero.val
 int
value to be converted to BigDecimal
.mc
 the context to use.ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
.public BigDecimal(long val)
long
into a BigDecimal
. The scale of the BigDecimal
is zero.val
 long
value to be converted to BigDecimal
.public BigDecimal(long val, MathContext mc)
long
into a BigDecimal
, with rounding according to the context settings. The scale
of the BigDecimal
, before any rounding, is zero.val
 long
value to be converted to BigDecimal
.mc
 the context to use.ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
.public BigDecimal(String val)
BigDecimal
into a BigDecimal
. The string representation
consists of an optional sign, '+'
( '\u002B') or ''
('\u002D'),
followed by a sequence of zero or more decimal digits ("the integer"), optionally followed by a fraction,
optionally followed by an exponent.
The fraction consists of a decimal point followed by zero or more decimal digits. The string must contain at least one digit in either the integer or the fraction. The number formed by the sign, the integer and the fraction is referred to as the significand.
The exponent consists of the character 'e'
('\u0065') or 'E'
('\u0045')
followed by one or more decimal digits. The value of the exponent must lie between Integer.MAX_VALUE
(
Integer.MIN_VALUE
+1) and Integer.MAX_VALUE
, inclusive.
More formally, the strings this constructor accepts are described by the following grammar:
 BigDecimalString:
 Sign_{opt} Significand Exponent_{opt}
 Sign:
+

 Significand:
 IntegerPart
.
FractionPart_{opt}.
FractionPart IntegerPart
 IntegerPart:
 Digits
 FractionPart:
 Digits
 Exponent:
 ExponentIndicator SignedInteger
 ExponentIndicator:
e
E
 SignedInteger:
 Sign_{opt} Digits
 Digits:
 Digit
 Digits Digit
 Digit:
 any character for which
Character.isDigit(char)
returnstrue
, including 0, 1, 2 ...
The scale of the returned BigDecimal
will be the number of digits in the fraction, or zero if the string
contains no decimal point, subject to adjustment for any exponent; if the string contains an exponent, the
exponent is subtracted from the scale. The value of the resulting scale must lie between
Integer.MIN_VALUE
and Integer.MAX_VALUE
, inclusive.
The charactertodigit mapping is provided by Character.digit(char, int)
set to convert to radix 10. The
String may not contain any extraneous characters (whitespace, for example).
Examples:
The value of the returned BigDecimal
is equal to significand × 10^{
exponent}. For each string on the left, the resulting representation [BigInteger
,
scale
] is shown on the right.
"0" [0,0] "0.00" [0,2] "123" [123,0] "123" [123,0] "1.23E3" [123,1] "1.23E+3" [123,1] "12.3E+7" [123,6] "12.0" [120,1] "12.3" [123,1] "0.00123" [123,5] "1.23E12" [123,14] "1234.5E4" [12345,5] "0E+7" [0,7] "0" [0,0]
Note: For values other than float
and double
NaN and ±Infinity, this constructor is
compatible with the values returned by Float.toString(float)
and Double.toString(double)
. This is generally the
preferred way to convert a float
or double
into a BigDecimal, as it doesn't suffer from the
unpredictability of the BigDecimal(double)
constructor.
val
 String representation of BigDecimal
.NumberFormatException
 if val
is not a valid representation of a BigDecimal
.public BigDecimal(String val, MathContext mc)
BigDecimal
into a BigDecimal
, accepting the same
strings as the BigDecimal(String)
constructor, with rounding according to the context settings.val
 string representation of a BigDecimal
.mc
 the context to use.ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
.NumberFormatException
 if val
is not a valid representation of a BigDecimal.public BigDecimal abs()
BigDecimal
whose value is the absolute value of this BigDecimal
, and whose scale is
this.scale()
.abs(this)
public BigDecimal abs(MathContext mc)
BigDecimal
whose value is the absolute value of this BigDecimal
, with rounding
according to the context settings.mc
 the context to use.abs(this)
, rounded as necessary.ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
.public BigDecimal add(BigDecimal augend)
BigDecimal
whose value is (this +
augend)
, and whose scale is max(this.scale(),
augend.scale())
.augend
 value to be added to this BigDecimal
.this + augend
public BigDecimal add(BigDecimal augend, MathContext mc)
BigDecimal
whose value is (this + augend)
, with rounding according to the context
settings.
If either number is zero and the precision setting is nonzero then the other number, rounded if necessary, is
used as the result.augend
 value to be added to this BigDecimal
.mc
 the context to use.this + augend
, rounded as necessary.ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
.public byte byteValueExact()
BigDecimal
to a byte
, checking for lost information. If this BigDecimal
has
a nonzero fractional part or is out of the possible range for a byte
result then an
ArithmeticException
is thrown.BigDecimal
converted to a byte
.ArithmeticException
 if this
has a nonzero fractional part, or will not fit in a byte
.public int compareTo(BigDecimal val)
BigDecimal
with the specified BigDecimal
. Two BigDecimal
objects that are
equal in value but have a different scale (like 2.0 and 2.00) are considered equal by this method. This method is
provided in preference to individual methods for each of the six boolean comparison operators (<, ==,
>, >=, !=, <=). The suggested idiom for performing these comparisons is:
(x.compareTo(y)
<op> 0)
, where <op> is one of the six comparison
operators.compareTo
in interface Comparable<BigDecimal>
val
 BigDecimal
to which this BigDecimal
is to be compared.BigDecimal
is numerically less than, equal to, or greater than val
.public BigDecimal divide(BigDecimal divisor)
BigDecimal
whose value is (this /
divisor)
, and whose preferred scale is (this.scale() 
divisor.scale())
; if the exact quotient cannot be represented (because it has a nonterminating decimal
expansion) an ArithmeticException
is thrown.divisor
 value by which this BigDecimal
is to be divided.this / divisor
ArithmeticException
 if the exact quotient does not have a terminating decimal expansionpublic BigDecimal divide(BigDecimal divisor, int roundingMode)
BigDecimal
whose value is (this /
divisor)
, and whose scale is this.scale()
. If rounding must be performed to generate a result with the
given scale, the specified rounding mode is applied.
The new divide(BigDecimal, RoundingMode)
method should be used in preference to this legacy method.
divisor
 value by which this BigDecimal
is to be divided.roundingMode
 rounding mode to apply.this / divisor
ArithmeticException
 if divisor==0
, or roundingMode==ROUND_UNNECESSARY
and this.scale()
is
insufficient to represent the result of the division exactly.IllegalArgumentException
 if roundingMode
does not represent a valid rounding mode.ROUND_UP
,
ROUND_DOWN
,
ROUND_CEILING
,
ROUND_FLOOR
,
ROUND_HALF_UP
,
ROUND_HALF_DOWN
,
ROUND_HALF_EVEN
,
ROUND_UNNECESSARY
public BigDecimal divide(BigDecimal divisor, int scale, int roundingMode)
BigDecimal
whose value is (this /
divisor)
, and whose scale is as specified. If rounding must be performed to generate a result with the specified
scale, the specified rounding mode is applied.
The new divide(BigDecimal, int, RoundingMode)
method should be used in preference to this legacy method.
divisor
 value by which this BigDecimal
is to be divided.scale
 scale of the BigDecimal
quotient to be returned.roundingMode
 rounding mode to apply.this / divisor
ArithmeticException
 if divisor
is zero, roundingMode==ROUND_UNNECESSARY
and the specified scale is
insufficient to represent the result of the division exactly.IllegalArgumentException
 if roundingMode
does not represent a valid rounding mode.ROUND_UP
,
ROUND_DOWN
,
ROUND_CEILING
,
ROUND_FLOOR
,
ROUND_HALF_UP
,
ROUND_HALF_DOWN
,
ROUND_HALF_EVEN
,
ROUND_UNNECESSARY
public BigDecimal divide(BigDecimal divisor, int scale, RoundingMode roundingMode)
BigDecimal
whose value is (this /
divisor)
, and whose scale is as specified. If rounding must be performed to generate a result with the specified
scale, the specified rounding mode is applied.divisor
 value by which this BigDecimal
is to be divided.scale
 scale of the BigDecimal
quotient to be returned.roundingMode
 rounding mode to apply.this / divisor
ArithmeticException
 if divisor
is zero, roundingMode==RoundingMode.UNNECESSARY
and the specified scale is
insufficient to represent the result of the division exactly.public BigDecimal divide(BigDecimal divisor, MathContext mc)
BigDecimal
whose value is (this /
divisor)
, with rounding according to the context settings.divisor
 value by which this BigDecimal
is to be divided.mc
 the context to use.this / divisor
, rounded as necessary.ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
or mc.precision == 0
and the quotient has a nonterminating decimal expansion.public BigDecimal divide(BigDecimal divisor, RoundingMode roundingMode)
BigDecimal
whose value is (this /
divisor)
, and whose scale is this.scale()
. If rounding must be performed to generate a result with the
given scale, the specified rounding mode is applied.divisor
 value by which this BigDecimal
is to be divided.roundingMode
 rounding mode to apply.this / divisor
ArithmeticException
 if divisor==0
, or roundingMode==RoundingMode.UNNECESSARY
and this.scale()
is
insufficient to represent the result of the division exactly.public BigDecimal[] divideAndRemainder(BigDecimal divisor)
BigDecimal
array containing the result of divideToIntegralValue
followed by
the result of remainder
on the two operands.
Note that if both the integer quotient and remainder are needed, this method is faster than using the
divideToIntegralValue
and remainder
methods separately because the division need only be carried
out once.
divisor
 value by which this BigDecimal
is to be divided, and the remainder computed.BigDecimal
array: the quotient (the result of divideToIntegralValue
) is the
initial element and the remainder is the final element.ArithmeticException
 if divisor==0
divideToIntegralValue(java.math.BigDecimal, java.math.MathContext)
,
remainder(java.math.BigDecimal, java.math.MathContext)
public BigDecimal[] divideAndRemainder(BigDecimal divisor, MathContext mc)
BigDecimal
array containing the result of divideToIntegralValue
followed by
the result of remainder
on the two operands calculated with rounding according to the context settings.
Note that if both the integer quotient and remainder are needed, this method is faster than using the
divideToIntegralValue
and remainder
methods separately because the division need only be carried
out once.
divisor
 value by which this BigDecimal
is to be divided, and the remainder computed.mc
 the context to use.BigDecimal
array: the quotient (the result of divideToIntegralValue
) is the
initial element and the remainder is the final element.ArithmeticException
 if divisor==0
ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
, or mc.precision
> 0 and the result of this.divideToIntgralValue(divisor)
would require a precision
of more than mc.precision
digits.divideToIntegralValue(java.math.BigDecimal, java.math.MathContext)
,
remainder(java.math.BigDecimal, java.math.MathContext)
public BigDecimal divideToIntegralValue(BigDecimal divisor)
BigDecimal
whose value is the integer part of the quotient (this / divisor)
rounded
down. The preferred scale of the result is (this.scale() 
divisor.scale())
.divisor
 value by which this BigDecimal
is to be divided.this / divisor
.ArithmeticException
 if divisor==0
public BigDecimal divideToIntegralValue(BigDecimal divisor, MathContext mc)
BigDecimal
whose value is the integer part of (this / divisor)
. Since the integer part
of the exact quotient does not depend on the rounding mode, the rounding mode does not affect the values returned
by this method. The preferred scale of the result is (this.scale()  divisor.scale())
. An
ArithmeticException
is thrown if the integer part of the exact quotient needs more than
mc.precision
digits.divisor
 value by which this BigDecimal
is to be divided.mc
 the context to use.this / divisor
.ArithmeticException
 if divisor==0
ArithmeticException
 if mc.precision
> 0 and the result requires a precision of more than
mc.precision
digits.public double doubleValue()
BigDecimal
to a double
. This conversion is similar to the narrowing primitive
conversion from double
to float
as defined in section 5.1.3 of The Java™ Language
Specification: if this BigDecimal
has too great a magnitude represent as a double
, it will
be converted to Double.NEGATIVE_INFINITY
or Double.POSITIVE_INFINITY
as appropriate. Note that
even when the return value is finite, this conversion can lose information about the precision of the
BigDecimal
value.doubleValue
in class Number
BigDecimal
converted to a double
.public boolean equals(@Nullable Object x)
BigDecimal
with the specified Object
for equality. Unlike
compareTo
, this method considers two BigDecimal
objects equal only if they
are equal in value and scale (thus 2.0 is not equal to 2.00 when compared by this method).equals
in class Object
x
 Object
to which this BigDecimal
is to be compared.true
if and only if the specified Object
is a BigDecimal
whose value and scale
are equal to this BigDecimal
's.compareTo(java.math.BigDecimal)
,
hashCode()
public float floatValue()
BigDecimal
to a float
. This conversion is similar to the narrowing primitive
conversion from double
to float
as defined in section 5.1.3 of The Java™ Language
Specification: if this BigDecimal
has too great a magnitude to represent as a float
, it
will be converted to Float.NEGATIVE_INFINITY
or Float.POSITIVE_INFINITY
as appropriate. Note that
even when the return value is finite, this conversion can lose information about the precision of the
BigDecimal
value.floatValue
in class Number
BigDecimal
converted to a float
.public int hashCode()
BigDecimal
. Note that two BigDecimal
objects that are numerically
equal but differ in scale (like 2.0 and 2.00) will generally not have the same hash code.hashCode
in class Object
BigDecimal
.equals(Object)
public int intValue()
BigDecimal
to an int
. This conversion is analogous to the narrowing primitive
conversion from double
to short
as defined in section 5.1.3 of The Java™ Language
Specification: any fractional part of this BigDecimal
will be discarded, and if the resulting
"BigInteger
" is too big to fit in an int
, only the loworder 32 bits are returned. Note that this
conversion can lose information about the overall magnitude and precision of this BigDecimal
value as
well as return a result with the opposite sign.public int intValueExact()
BigDecimal
to an int
, checking for lost information. If this BigDecimal
has
a nonzero fractional part or is out of the possible range for an int
result then an
ArithmeticException
is thrown.BigDecimal
converted to an int
.ArithmeticException
 if this
has a nonzero fractional part, or will not fit in an int
.public long longValue()
BigDecimal
to a long
. This conversion is analogous to the narrowing primitive
conversion from double
to short
as defined in section 5.1.3 of The Java™ Language
Specification: any fractional part of this BigDecimal
will be discarded, and if the resulting
"BigInteger
" is too big to fit in a long
, only the loworder 64 bits are returned. Note that this
conversion can lose information about the overall magnitude and precision of this BigDecimal
value as
well as return a result with the opposite sign.public long longValueExact()
BigDecimal
to a long
, checking for lost information. If this BigDecimal
has
a nonzero fractional part or is out of the possible range for a long
result then an
ArithmeticException
is thrown.BigDecimal
converted to a long
.ArithmeticException
 if this
has a nonzero fractional part, or will not fit in a long
.public BigDecimal max(BigDecimal val)
BigDecimal
and val
.val
 value with which the maximum is to be computed.BigDecimal
whose value is the greater of this BigDecimal
and val
. If they are
equal, as defined by the compareTo
method, this
is returned.compareTo(java.math.BigDecimal)
public BigDecimal min(BigDecimal val)
BigDecimal
and val
.val
 value with which the minimum is to be computed.BigDecimal
whose value is the lesser of this BigDecimal
and val
. If they are
equal, as defined by the compareTo
method, this
is returned.compareTo(java.math.BigDecimal)
public BigDecimal movePointLeft(int n)
BigDecimal
which is equivalent to this one with the decimal point moved n
places to the
left. If n
is nonnegative, the call merely adds n
to the scale. If n
is negative, the
call is equivalent to movePointRight(n)
. The BigDecimal
returned by this call has value
(this ×
10^{n}) and scale max(this.scale()+n,
0)
.n
 number of places to move the decimal point to the left.BigDecimal
which is equivalent to this one with the decimal point moved n
places to the
left.ArithmeticException
 if scale overflows.public BigDecimal movePointRight(int n)
BigDecimal
which is equivalent to this one with the decimal point moved n
places to the
right. If n
is nonnegative, the call merely subtracts n
from the scale. If n
is
negative, the call is equivalent to movePointLeft(n)
. The BigDecimal
returned by this call has
value (this
× 10^{n}) and scale max(this.scale()n,
0)
.n
 number of places to move the decimal point to the right.BigDecimal
which is equivalent to this one with the decimal point moved n
places to the
right.ArithmeticException
 if scale overflows.public BigDecimal multiply(BigDecimal multiplicand)
BigDecimal
whose value is (this ×
multiplicand), and whose scale is (this.scale() +
multiplicand.scale())
.multiplicand
 value to be multiplied by this BigDecimal
.this * multiplicand
public BigDecimal multiply(BigDecimal multiplicand, MathContext mc)
BigDecimal
whose value is (this ×
multiplicand), with rounding according to the context settings.multiplicand
 value to be multiplied by this BigDecimal
.mc
 the context to use.this * multiplicand
, rounded as necessary.ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
.public BigDecimal negate()
BigDecimal
whose value is (this)
, and whose scale is this.scale()
.this
.public BigDecimal negate(MathContext mc)
BigDecimal
whose value is (this)
, with rounding according to the context settings.mc
 the context to use.this
, rounded as necessary.ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
.public BigDecimal plus()
BigDecimal
whose value is (+this)
, and whose scale is this.scale()
.
This method, which simply returns this BigDecimal
is included for symmetry with the unary minus method
negate()
.
this
.negate()
public BigDecimal plus(MathContext mc)
BigDecimal
whose value is (+this)
, with rounding according to the context settings.
The effect of this method is identical to that of the round(MathContext)
method.
mc
 the context to use.this
, rounded as necessary. A zero result will have a scale of 0.ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
.round(MathContext)
public BigDecimal pow(int n)
BigDecimal
whose value is (this^{n}), The power is computed exactly, to
unlimited precision.
The parameter n
must be in the range 0 through 999999999, inclusive. ZERO.pow(0)
returns
ONE
.
Note that future releases may expand the allowable exponent range of this method.
n
 power to raise this BigDecimal
to.ArithmeticException
 if n
is out of range.public BigDecimal pow(int n, MathContext mc)
BigDecimal
whose value is (this^{n}). The current implementation uses the core
algorithm defined in ANSI standard X3.2741996 with rounding according to the context settings. In general, the
returned numerical value is within two ulps of the exact numerical value for the chosen precision. Note that
future releases may use a different algorithm with a decreased allowable error bound and increased allowable
exponent range.
The X3.2741996 algorithm is:
ArithmeticException
exception is thrown if
abs(n) > 999999999
mc.precision == 0
and n < 0
mc.precision > 0
and n
has more than mc.precision
decimal digits
n
is zero, ONE
is returned even if this
is zero, otherwise
n
is positive, the result is calculated via the repeated squaring technique into a single
accumulator. The individual multiplications with the accumulator use the same math context settings as in
mc
except for a precision increased to mc.precision + elength + 1
where elength
is the
number of decimal digits in n
.
n
is negative, the result is calculated as if n
were positive; this value is then divided
into one using the working precision specified above.
n
 power to raise this BigDecimal
to.mc
 the context to use.ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
, or n
is out of range.public int precision()
BigDecimal
. (The precision is the number of digits in the unscaled
value.)
The precision of a zero value is 1.
BigDecimal
.public BigDecimal remainder(BigDecimal divisor)
BigDecimal
whose value is (this % divisor)
.
The remainder is given by this.subtract(this.divideToIntegralValue(divisor).multiply(divisor))
. Note that
this is not the modulo operation (the result can be negative).
divisor
 value by which this BigDecimal
is to be divided.this % divisor
.ArithmeticException
 if divisor==0
public BigDecimal remainder(BigDecimal divisor, MathContext mc)
BigDecimal
whose value is (this %
divisor)
, with rounding according to the context settings. The MathContext
settings affect the implicit
divide used to compute the remainder. The remainder computation itself is by definition exact. Therefore, the
remainder may contain more than mc.getPrecision()
digits.
The remainder is given by this.subtract(this.divideToIntegralValue(divisor,
mc).multiply(divisor))
. Note that this is not the modulo operation (the result can be negative).
divisor
 value by which this BigDecimal
is to be divided.mc
 the context to use.this % divisor
, rounded as necessary.ArithmeticException
 if divisor==0
ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
, or mc.precision
> 0 and the result of this.divideToIntgralValue(divisor)
would require a precision
of more than mc.precision
digits.divideToIntegralValue(java.math.BigDecimal, java.math.MathContext)
public BigDecimal round(MathContext mc)
BigDecimal
rounded according to the MathContext
settings. If the precision setting is 0
then no rounding takes place.
The effect of this method is identical to that of the plus(MathContext)
method.
mc
 the context to use.BigDecimal
rounded according to the MathContext
settings.ArithmeticException
 if the rounding mode is UNNECESSARY
and the BigDecimal
operation would require
rounding.plus(MathContext)
public int scale()
BigDecimal
. If zero or positive, the scale is the number of digits to
the right of the decimal point. If negative, the unscaled value of the number is multiplied by ten to the power
of the negation of the scale. For example, a scale of 3
means the unscaled value is multiplied by 1000.BigDecimal
.public BigDecimal scaleByPowerOfTen(int n)
this
* 10^{n}). The scale of the result
is (this.scale()  n)
.n
 the exponent power of ten to scale bythis
* 10^{n})ArithmeticException
 if the scale would be outside the range of a 32bit integer.public BigDecimal setScale(int newScale)
BigDecimal
whose scale is the specified value, and whose value is numerically equal to this
BigDecimal
's. Throws an ArithmeticException
if this is not possible.
This call is typically used to increase the scale, in which case it is guaranteed that there exists a
BigDecimal
of the specified scale and the correct value. The call can also be used to reduce the scale if
the caller knows that the BigDecimal
has sufficiently many zeros at the end of its fractional part (i.e.,
factors of ten in its integer value) to allow for the rescaling without changing its value.
This method returns the same result as the twoargument versions of setScale
, but saves the caller the
trouble of specifying a rounding mode in cases where it is irrelevant.
Note that since BigDecimal
objects are immutable, calls of this method do not result in the
original object being modified, contrary to the usual convention of having methods named setX
mutate field X
. Instead, setScale
returns an object with the proper scale; the returned
object may or may not be newly allocated.
newScale
 scale of the BigDecimal
value to be returned.BigDecimal
whose scale is the specified value, and whose unscaled value is determined by
multiplying or dividing this BigDecimal
's unscaled value by the appropriate power of ten to
maintain its overall value.ArithmeticException
 if the specified scaling operation would require rounding.setScale(int, int)
,
setScale(int, RoundingMode)
public BigDecimal setScale(int newScale, int roundingMode)
BigDecimal
whose scale is the specified value, and whose unscaled value is determined by
multiplying or dividing this BigDecimal
's unscaled value by the appropriate power of ten to maintain its
overall value. If the scale is reduced by the operation, the unscaled value must be divided (rather than
multiplied), and the value may be changed; in this case, the specified rounding mode is applied to the division.
Note that since BigDecimal objects are immutable, calls of this method do not result in the original
object being modified, contrary to the usual convention of having methods named setX mutate field
X
. Instead, setScale
returns an object with the proper scale; the returned object may or
may not be newly allocated.
The new setScale(int, RoundingMode)
method should be used in preference to this legacy method.
newScale
 scale of the BigDecimal
value to be returned.roundingMode
 The rounding mode to apply.BigDecimal
whose scale is the specified value, and whose unscaled value is determined by
multiplying or dividing this BigDecimal
's unscaled value by the appropriate power of ten to
maintain its overall value.ArithmeticException
 if roundingMode==ROUND_UNNECESSARY
and the specified scaling operation would require
rounding.IllegalArgumentException
 if roundingMode
does not represent a valid rounding mode.ROUND_UP
,
ROUND_DOWN
,
ROUND_CEILING
,
ROUND_FLOOR
,
ROUND_HALF_UP
,
ROUND_HALF_DOWN
,
ROUND_HALF_EVEN
,
ROUND_UNNECESSARY
public BigDecimal setScale(int newScale, RoundingMode roundingMode)
BigDecimal
whose scale is the specified value, and whose unscaled value is determined by
multiplying or dividing this BigDecimal
's unscaled value by the appropriate power of ten to maintain its
overall value. If the scale is reduced by the operation, the unscaled value must be divided (rather than
multiplied), and the value may be changed; in this case, the specified rounding mode is applied to the division.
Note that since BigDecimal objects are immutable, calls of this method do not result in the original
object being modified, contrary to the usual convention of having methods named setX mutate field
X
. Instead, setScale
returns an object with the proper scale; the returned object may or
may not be newly allocated.
newScale
 scale of the BigDecimal
value to be returned.roundingMode
 The rounding mode to apply.BigDecimal
whose scale is the specified value, and whose unscaled value is determined by
multiplying or dividing this BigDecimal
's unscaled value by the appropriate power of ten to
maintain its overall value.ArithmeticException
 if roundingMode==UNNECESSARY
and the specified scaling operation would require rounding.RoundingMode
public short shortValueExact()
BigDecimal
to a short
, checking for lost information. If this BigDecimal
has a nonzero fractional part or is out of the possible range for a short
result then an
ArithmeticException
is thrown.BigDecimal
converted to a short
.ArithmeticException
 if this
has a nonzero fractional part, or will not fit in a short
.public int signum()
BigDecimal
.BigDecimal
is negative, zero, or positive.public BigDecimal stripTrailingZeros()
BigDecimal
which is numerically equal to this one but with any trailing zeros removed from the
representation. For example, stripping the trailing zeros from the BigDecimal
value 600.0
, which
has [BigInteger
, scale
] components equals to [6000, 1], yields 6E2
with [
BigInteger
, scale
] components equals to [6, 2]. If this BigDecimal is numerically equal to zero,
then BigDecimal.ZERO
is returned.BigDecimal
with any trailing zeros removed.public BigDecimal subtract(BigDecimal subtrahend)
BigDecimal
whose value is (this 
subtrahend)
, and whose scale is max(this.scale(),
subtrahend.scale())
.subtrahend
 value to be subtracted from this BigDecimal
.this  subtrahend
public BigDecimal subtract(BigDecimal subtrahend, MathContext mc)
BigDecimal
whose value is (this  subtrahend)
, with rounding according to the context
settings.
If subtrahend
is zero then this, rounded if necessary, is used as the result. If this is zero then the
result is subtrahend.negate(mc)
.subtrahend
 value to be subtracted from this BigDecimal
.mc
 the context to use.this  subtrahend
, rounded as necessary.ArithmeticException
 if the result is inexact but the rounding mode is UNNECESSARY
.public BigInteger toBigInteger()
BigDecimal
to a BigInteger
. This conversion is analogous to the narrowing
primitive conversion from double
to long
as defined in section 5.1.3 of The Java™
Language Specification: any fractional part of this BigDecimal
will be discarded. Note that this
conversion can lose information about the precision of the BigDecimal
value.
To have an exception thrown if the conversion is inexact (in other words if a nonzero fractional part is
discarded), use the toBigIntegerExact()
method.
BigDecimal
converted to a BigInteger
.public BigInteger toBigIntegerExact()
BigDecimal
to a BigInteger
, checking for lost information. An exception is thrown
if this BigDecimal
has a nonzero fractional part.BigDecimal
converted to a BigInteger
.ArithmeticException
 if this
has a nonzero fractional part.public String toEngineeringString()
BigDecimal
, using engineering notation if an exponent is needed.
Returns a string that represents the BigDecimal
as described in the toString()
method, except
that if exponential notation is used, the power of ten is adjusted to be a multiple of three (engineering
notation) such that the integer part of nonzero values will be in the range 1 through 999. If exponential
notation is used for zero values, a decimal point and one or two fractional zero digits are used so that the
scale of the zero value is preserved. Note that unlike the output of toString()
, the output of this
method is not guaranteed to recover the same [integer, scale] pair of this BigDecimal
if the
output string is converting back to a BigDecimal
using the string
constructor. The result of this method meets the weaker constraint of always producing a numerically equal
result from applying the string constructor to the method's output.
BigDecimal
, using engineering notation if an exponent is needed.public String toPlainString()
BigDecimal
without an exponent field. For values with a positive
scale, the number of digits to the right of the decimal point is used to indicate scale. For values with a zero
or negative scale, the resulting string is generated as if the value were converted to a numerically equal value
with zero scale and as if all the trailing zeros of the zero scale value were present in the result.
The entire string is prefixed by a minus sign character '' ('\u002D') if the unscaled value is less
than zero. No sign character is prefixed if the unscaled value is zero or positive.
Note that if the result of this method is passed to the string constructor, only
the numerical value of this BigDecimal
will necessarily be recovered; the representation of the new
BigDecimal
may have a different scale. In particular, if this BigDecimal
has a negative scale,
the string resulting from this method will have a scale of zero when processed by the string constructor.
(This method behaves analogously to the toString
method in 1.4 and earlier releases.)BigDecimal
without an exponent field.toString()
,
toEngineeringString()
public String toString()
BigDecimal
, using scientific notation if an exponent is needed.
A standard canonical string form of the BigDecimal
is created as though by the following steps: first,
the absolute value of the unscaled value of the BigDecimal
is converted to a string in base ten using the
characters '0'
through '9'
with no leading zeros (except if its value is zero, in which case a
single '0'
character is used).
Next, an adjusted exponent is calculated; this is the negated scale, plus the number of characters in the
converted unscaled value, less one. That is, scale+(ulength1)
, where ulength
is the length of
the absolute value of the unscaled value in decimal digits (its precision).
If the scale is greater than or equal to zero and the adjusted exponent is greater than or equal to 6
,
the number will be converted to a character form without using exponential notation. In this case, if the scale
is zero then no decimal point is added and if the scale is positive a decimal point will be inserted with the
scale specifying the number of characters to the right of the decimal point. '0'
characters are added to
the left of the converted unscaled value as necessary. If no character precedes the decimal point after this
insertion then a conventional '0'
character is prefixed.
Otherwise (that is, if the scale is negative, or the adjusted exponent is less than 6
), the number will
be converted to a character form using exponential notation. In this case, if the converted BigInteger
has more than one digit a decimal point is inserted after the first digit. An exponent in character form is then
suffixed to the converted unscaled value (perhaps with inserted decimal point); this comprises the letter
'E'
followed immediately by the adjusted exponent converted to a character form. The latter is in base
ten, using the characters '0'
through '9'
with no leading zeros, and is always prefixed by a sign
character ''
('\u002D') if the adjusted exponent is negative, '+'
(
'\u002B') otherwise).
Finally, the entire string is prefixed by a minus sign character ''
('\u002D') if the
unscaled value is less than zero. No sign character is prefixed if the unscaled value is zero or positive.
Examples:
For each representation [unscaled value, scale] on the left, the resulting string is shown on the right.
[123,0] "123" [123,0] "123" [123,1] "1.23E+3" [123,3] "1.23E+5" [123,1] "12.3" [123,5] "0.00123" [123,10] "1.23E8" [123,12] "1.23E10"Notes:
BigDecimal
values and the result of this
conversion. That is, every distinguishable BigDecimal
value (unscaled value and scale) has a unique
string representation as a result of using toString
. If that string representation is converted back to a
BigDecimal
using the BigDecimal(String)
constructor, then the original value will be recovered.
toEngineeringString()
method may be used for presenting numbers with exponents in engineering
notation, and the setScale
method may be used for rounding a
BigDecimal
so it has a known number of digits after the decimal point.
Character.forDigit
is used.
toString
in class Object
BigDecimal
.Character.forDigit(int, int)
,
BigDecimal(java.lang.String)
public BigDecimal ulp()
BigDecimal
. An ulp of a nonzero
BigDecimal
value is the positive distance between this value and the BigDecimal
value next larger
in magnitude with the same number of digits. An ulp of a zero value is numerically equal to 1 with the scale of
this
. The result is stored with the same scale as this
so the result for zero and nonzero values
is equal to [1,
this.scale()]
.this
public BigInteger unscaledValue()
BigInteger
whose value is the unscaled value of this BigDecimal
. (Computes
(this *
10^{this.scale()}).)BigDecimal
.public static BigDecimal valueOf(double val)
double
into a BigDecimal
, using the double
's canonical string representation
provided by the Double.toString(double)
method.
Note: This is generally the preferred way to convert a double
(or float
) into a
BigDecimal
, as the value returned is equal to that resulting from constructing a BigDecimal
from
the result of using Double.toString(double)
.
val
 double
to convert to a BigDecimal
.BigDecimal
whose value is equal to or approximately equal to the value of val
.NumberFormatException
 if val
is infinite or NaN.public static BigDecimal valueOf(long val)
long
value into a BigDecimal
with a scale of zero. This
"static factory method" is provided in preference to a (long
) constructor because it allows
for reuse of frequently used BigDecimal
values.val
 value of the BigDecimal
.BigDecimal
whose value is val
.public static BigDecimal valueOf(long unscaledVal, int scale)
long
unscaled value and an int
scale into a BigDecimal
. This
"static factory method" is provided in preference to a (long
, int
) constructor because
it allows for reuse of frequently used BigDecimal
values..unscaledVal
 unscaled value of the BigDecimal
.scale
 scale of the BigDecimal
.BigDecimal
whose value is (unscaledVal × 10^{scale}).