java.lang
Class Long
java.lang.Object
java.lang.Long
public final class Long
- extends Object
The Long class wraps a value of the primitive type long in an object. An object of type Long contains a
single field whose type is long.
In addition, this class provides several methods for converting a long to a String and a String to a long,
as well as other constants and methods useful when dealing with a long.
|
Field Summary |
static long |
MAX_VALUE
The largest value of type long. |
static long |
MIN_VALUE
The smallest value of type long. |
|
Constructor Summary |
Long(long value)
Constructs a newly allocated Long object that represents the primitive long argument. |
|
Method Summary |
double |
doubleValue()
Returns the value of this Long as a double. |
boolean |
equals(Object obj)
Compares this object against the specified object. |
float |
floatValue()
Returns the value of this Long as a float. |
int |
hashCode()
Computes a hashcode for this Long. |
long |
longValue()
Returns the value of this Long as a long value. |
static long |
parseLong(String s)
Parses the string argument as a signed decimal long. |
static long |
parseLong(String s,
int radix)
Parses the string argument as a signed long in the radix specified by the second argument. |
String |
toString()
Returns a String object representing this Long's value. |
static String |
toString(long i)
Returns a new String object representing the specified integer. |
static String |
toString(long i,
int radix)
Creates a string representation of the first argument in the radix specified by the second argument. |
MIN_VALUE
public static final long MIN_VALUE
- The smallest value of type long.
- See Also:
- Constant Field Values
MAX_VALUE
public static final long MAX_VALUE
- The largest value of type long.
- See Also:
- Constant Field Values
Long
public Long(long value)
- Constructs a newly allocated Long object that represents the primitive long argument.
doubleValue
public double doubleValue()
- Returns the value of this Long as a double.
equals
public boolean equals(Object obj)
- Compares this object against the specified object. The result is true if and only if the argument is
not null and is a Long object that contains the same long value as this object.
- Overrides:
equals in class Object
- Parameters:
obj - the reference object with which to compare.
- Returns:
- true if this object is the same as the obj argument; false otherwise.
floatValue
public float floatValue()
- Returns the value of this Long as a float.
hashCode
public int hashCode()
- Computes a hashcode for this Long. The result is the exclusive OR of the
two halves of the primitive long value represented by this Long object.
That is, the hashcode is the value of the expression:
(int)(this.longValue()^(this.longValue()>>>32))
- Overrides:
hashCode in class Object
longValue
public long longValue()
- Returns the value of this Long as a long value.
parseLong
public static long parseLong(String s)
throws NumberFormatException
- Parses the string argument as a signed decimal long. The characters in the string must all be
decimal digits, except that the first character may be an ASCII minus sign '-' (-') to
indicate a negative value. The resulting long value is returned, exactly as if the argument and the
radix 10 were given as arguments to the parseLong(String, int) method that takes two
arguments.
Note that neither L nor l is permitted to appear at the end of the string as a type indicator, as would
be permitted in Java programming language source code.
- Throws:
NumberFormatException
parseLong
public static long parseLong(String s,
int radix)
throws NumberFormatException
- Parses the string argument as a signed long in the radix specified by the second argument. The
characters in the string must all be digits of the specified radix (as determined by whether
Character.digit returns a nonnegative value), except that the first character may be an ASCII
minus sign '-' ('-' to indicate a negative value. The resulting long value is returned.
Note that neither L nor l is permitted to appear at the end of the string as a type indicator, as would
be permitted in Java programming language source code - except that either L or l may appear as a
digit for a radix greater than 22.
An exception of type NumberFormatException is thrown if any of the following situations occurs:
The first argument is null or is a string of length zero.
The radix is either smaller than Character.MIN_RADIX or larger than Character.MAX_RADIX.
The first character of the string is not a digit of the specified radix and is not a minus sign '-' ('-').
The first character of the string is a minus sign and the string is of length 1. Any character of the string
after the first is not a digit of the specified radix. The integer value represented by the string cannot
be represented as a value of type long.
Examples:
parseLong("0", 10) returns 0L
parseLong("473", 10) returns 473L
parseLong("-0", 10) returns 0L
parseLong("-FF", 16) returns -255L
parseLong("1100110", 2) returns 102L
parseLong("99", 8) throws a NumberFormatException
parseLong("Hazelnut", 10) throws a NumberFormatException
parseLong("Hazelnut", 36) returns 1356099454469L
- Throws:
NumberFormatException
toString
public String toString()
- Returns a String object representing this Long's value. The long integer value represented by this
Long object is converted to signed decimal representation and returned as a string, exactly as if the
long value were given as an argument to the toString(long) method that takes one argument.
- Overrides:
toString in class Object
toString
public static String toString(long i)
- Returns a new String object representing the specified integer. The argument is converted to signed
decimal representation and returned as a string, exactly as if the argument and the radix 10 were
given as arguments to the toString(long, int) method that takes two arguments.
toString
public static String toString(long i,
int radix)
- Creates a string representation of the first argument in the radix specified by the second argument.
If the radix is smaller than Character.MIN_RADIX or larger than Character.MAX_RADIX, then the
radix 10 is used instead.
If the first argument is negative, the first element of the result is the ASCII minus sign '-' ('-'. If the first
argument is not negative, no sign character appears in the result.
The remaining characters of the result represent the magnitude of the first argument. If the
magnitude is zero, it is represented by a single zero character '0' ('0'); otherwise, the first
character of the representation of the magnitude will not be the zero character. The following ASCII
characters are used as digits:
0123456789abcdefghijklmnopqrstuvwxyz
These are '0' through '9' and 'a' through 'z'. If the radix is N, then the
first N of these characters are used as radix-N digits in the order shown. Thus, the digits for
hexadecimal (radix 16) are 0123456789abcdef.