*java.lang.Long* *Long* The Long class wraps a value of the primitive type
long
public final class Long
extends |java.lang.Number|
implements |java.lang.Comparable|
|java.lang.Long_Description|
|java.lang.Long_Fields|
|java.lang.Long_Constructors|
|java.lang.Long_Methods|
================================================================================
*java.lang.Long_Fields*
|long_java.lang.Long.MAX_VALUE|
|long_java.lang.Long.MIN_VALUE|
|int_java.lang.Long.SIZE|
|java.lang.Class<java.lang.Long>_java.lang.Long.TYPE|
*java.lang.Long_Constructors*
|java.lang.Long(long)|Constructs a newly allocated Long object that represents
|java.lang.Long(String)|Constructs a newly allocated Long object that represen
*java.lang.Long_Methods*
|java.lang.Long.bitCount(long)|Returns the number of one-bits in the two's comp
|java.lang.Long.byteValue()|Returns the value of this Long as a byte.
|java.lang.Long.compareTo(Long)|Compares two Long objects numerically.
|java.lang.Long.decode(String)|Decodes a String into a Long.
|java.lang.Long.doubleValue()|Returns the value of this Long as a double.
|java.lang.Long.equals(Object)|Compares this object to the specified object.
|java.lang.Long.floatValue()|Returns the value of this Long as a float.
|java.lang.Long.getLong(String)|Determines the long value of the system propert
|java.lang.Long.getLong(String,long)|Determines the long value of the system pr
|java.lang.Long.getLong(String,Long)|Returns the long value of the system prope
|java.lang.Long.hashCode()|Returns a hash code for this Long.
|java.lang.Long.highestOneBit(long)|Returns a long value with at most a single
|java.lang.Long.intValue()|Returns the value of this Long as an int.
|java.lang.Long.longValue()|Returns the value of this Long as a long value.
|java.lang.Long.lowestOneBit(long)|Returns a long value with at most a single o
|java.lang.Long.numberOfLeadingZeros(long)|Returns the number of zero bits prec
|java.lang.Long.numberOfTrailingZeros(long)|Returns the number of zero bits fol
|java.lang.Long.parseLong(String)|Parses the string argument as a signed decima
|java.lang.Long.parseLong(String,int)|Parses the string argument as a signed lo
|java.lang.Long.reverse(long)|Returns the value obtained by reversing the order
|java.lang.Long.reverseBytes(long)|Returns the value obtained by reversing the
|java.lang.Long.rotateLeft(long,int)|Returns the value obtained by rotating the
|java.lang.Long.rotateRight(long,int)|Returns the value obtained by rotating th
|java.lang.Long.shortValue()|Returns the value of this Long as a short.
|java.lang.Long.signum(long)|Returns the signum function of the specified long
|java.lang.Long.toBinaryString(long)|Returns a string representation of the lon
|java.lang.Long.toHexString(long)|Returns a string representation of the long
|java.lang.Long.toOctalString(long)|Returns a string representation of the long
|java.lang.Long.toString()|Returns a String object representing this Long's va
|java.lang.Long.toString(long)|Returns a String object representing the specifi
|java.lang.Long.toString(long,int)|Returns a string representation of the first
|java.lang.Long.valueOf(long)|Returns a Long instance representing the specifie
|java.lang.Long.valueOf(String)|Returns a Long object holding the value of the
|java.lang.Long.valueOf(String,int)|Returns a Long object holding the value ex
*java.lang.Long_Description*
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.
Implementation note: The implementations of the "bit twiddling" methods (such
as highestOneBit(|java.lang.Long|) and numberOfTrailingZeros(|java.lang.Long|)
) are based on material from Henry S. Warren, Jr.'s Hacker's Delight, (Addison
Wesley, 2002).
*long_java.lang.Long.MAX_VALUE*
A constant holding the maximum value a long can have, 263-1.
*long_java.lang.Long.MIN_VALUE*
A constant holding the minimum value a long can have, -263.
*int_java.lang.Long.SIZE*
The number of bits used to represent a long value in two's complement binary
form.
*java.lang.Class<java.lang.Long>_java.lang.Long.TYPE*
The Class instance representing the primitive type long.
*java.lang.Long(long)*
public Long(long value)
Constructs a newly allocated Long object that represents the specified long
argument.
value - the value to be represented by the Long object.
*java.lang.Long(String)*
public Long(java.lang.String s)
throws |java.lang.NumberFormatException|
Constructs a newly allocated Long object that represents the long value
indicated by the String parameter. The string is converted to a long value in
exactly the manner used by the parseLong method for radix 10.
s - the String to be converted to a Long.
*java.lang.Long.bitCount(long)*
public static int bitCount(long i)
Returns the number of one-bits in the two's complement binary representation of
the specified long value. This function is sometimes referred to as the
population count.
Returns: the number of one-bits in the two's complement binary representation of the
specified long value.
*java.lang.Long.byteValue()*
public byte byteValue()
Returns the value of this Long as a byte.
*java.lang.Long.compareTo(Long)*
public int compareTo(java.lang.Long anotherLong)
Compares two Long objects numerically.
anotherLong - the Long to be compared.
Returns: the value 0 if this Long is equal to the argument Long; a value less than 0 if
this Long is numerically less than the argument Long; and a value
greater than 0 if this Long is numerically greater than the
argument Long (signed comparison).
*java.lang.Long.decode(String)*
public static |java.lang.Long| decode(java.lang.String nm)
throws |java.lang.NumberFormatException|
Decodes a String into a Long. Accepts decimal, hexadecimal, and octal numbers
given by the following grammar:
DecodableString: Signopt DecimalNumeral Signopt 0x HexDigits Signopt 0X
HexDigits Signopt # HexDigits Signopt 0 OctalDigits
Sign: -
DecimalNumeral, HexDigits, and OctalDigits are defined in 3.10.1 of the Java
Language Specification.
The sequence of characters following an (optional) negative sign and/or radix
specifier (0x, 0X, #, or leading zero) is parsed as by the Long.parseLong
method with the indicated radix (10, 16, or 8). This sequence of characters
must represent a positive value or a (|java.lang.NumberFormatException|) will
be thrown. The result is negated if first character of the specified String is
the minus sign. No whitespace characters are permitted in the String.
nm - the String to decode.
Returns: a Long object holding the long value represented by nm
*java.lang.Long.doubleValue()*
public double doubleValue()
Returns the value of this Long as a double.
*java.lang.Long.equals(Object)*
public boolean equals(java.lang.Object obj)
Compares this object to 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.
obj - the object to compare with.
Returns: true if the objects are the same; false otherwise.
*java.lang.Long.floatValue()*
public float floatValue()
Returns the value of this Long as a float.
*java.lang.Long.getLong(String)*
public static |java.lang.Long| getLong(java.lang.String nm)
Determines the long value of the system property with the specified name.
The first argument is treated as the name of a system property. System
properties are accessible through the (|java.lang.System|) method. The string
value of this property is then interpreted as a long value and a Long object
representing this value is returned. Details of possible numeric formats can be
found with the definition of getProperty.
If there is no property with the specified name, if the specified name is empty
or null, or if the property does not have the correct numeric format, then null
is returned.
In other words, this method returns a Long object equal to the value of:
getLong(nm, null)
nm - property name.
Returns: the Long value of the property.
*java.lang.Long.getLong(String,long)*
public static |java.lang.Long| getLong(
java.lang.String nm,
long val)
Determines the long value of the system property with the specified name.
The first argument is treated as the name of a system property. System
properties are accessible through the (|java.lang.System|) method. The string
value of this property is then interpreted as a long value and a Long object
representing this value is returned. Details of possible numeric formats can be
found with the definition of getProperty.
The second argument is the default value. A Long object that represents the
value of the second argument is returned if there is no property of the
specified name, if the property does not have the correct numeric format, or if
the specified name is empty or null.
In other words, this method returns a Long object equal to the value of:
getLong(nm, new Long(val))
but in practice it may be implemented in a manner such as:
Long result = getLong(nm, null); return (result == null) ? new Long(val) :
result;
to avoid the unnecessary allocation of a Long object when the default value is
not needed.
nm - property name.
val - default value.
Returns: the Long value of the property.
*java.lang.Long.getLong(String,Long)*
public static |java.lang.Long| getLong(
java.lang.String nm,
java.lang.Long val)
Returns the long value of the system property with the specified name. The
first argument is treated as the name of a system property. System properties
are accessible through the (|java.lang.System|) method. The string value of
this property is then interpreted as a long value, as per the Long.decode
method, and a Long object representing this value is returned.
If the property value begins with the two ASCII characters 0x or the ASCII
character #, not followed by a minus sign, then the rest of it is parsed as a
hexadecimal integer exactly as for the method (|java.lang.Long|) with radix 16.
If the property value begins with the ASCII character 0 followed by another
character, it is parsed as an octal integer exactly as by the method
(|java.lang.Long|) with radix 8. Otherwise the property value is parsed as a
decimal integer exactly as by the method (|java.lang.Long|) with radix 10.
Note that, in every case, neither L ('u004C') nor l ('u006C') is permitted to
appear at the end of the property value as a type indicator, as would be
permitted in Java programming language source code.
The second argument is the default value. The default value is returned if
there is no property of the specified name, if the property does not have the
correct numeric format, or if the specified name is empty or null.
nm - property name.
val - default value.
Returns: the Long value of the property.
*java.lang.Long.hashCode()*
public int hashCode()
Returns a hash code for this Long. The result is the exclusive OR of the two
halves of the primitive long value held by this Long object. That is, the
hashcode is the value of the expression:
(int)(this.longValue()^(this.longValue()>>>32))
Returns: a hash code value for this object.
*java.lang.Long.highestOneBit(long)*
public static long highestOneBit(long i)
Returns a long value with at most a single one-bit, in the position of the
highest-order ("leftmost") one-bit in the specified long value. Returns zero if
the specified value has no one-bits in its two's complement binary
representation, that is, if it is equal to zero.
Returns: a long value with a single one-bit, in the position of the highest-order
one-bit in the specified value, or zero if the specified value is
itself equal to zero.
*java.lang.Long.intValue()*
public int intValue()
Returns the value of this Long as an int.
*java.lang.Long.longValue()*
public long longValue()
Returns the value of this Long as a long value.
*java.lang.Long.lowestOneBit(long)*
public static long lowestOneBit(long i)
Returns a long value with at most a single one-bit, in the position of the
lowest-order ("rightmost") one-bit in the specified long value. Returns zero if
the specified value has no one-bits in its two's complement binary
representation, that is, if it is equal to zero.
Returns: a long value with a single one-bit, in the position of the lowest-order one-bit
in the specified value, or zero if the specified value is itself
equal to zero.
*java.lang.Long.numberOfLeadingZeros(long)*
public static int numberOfLeadingZeros(long i)
Returns the number of zero bits preceding the highest-order ("leftmost")
one-bit in the two's complement binary representation of the specified long
value. Returns 64 if the specified value has no one-bits in its two's
complement representation, in other words if it is equal to zero.
Note that this method is closely related to the logarithm base 2. For all
positive long values x:
floor(log2(x)) = 63 - numberOfLeadingZeros(x) ceil(log2(x)) = 64 -
numberOfLeadingZeros(x - 1)
Returns: the number of zero bits preceding the highest-order ("leftmost") one-bit in the
two's complement binary representation of the specified long
value, or 64 if the value is equal to zero.
*java.lang.Long.numberOfTrailingZeros(long)*
public static int numberOfTrailingZeros(long i)
Returns the number of zero bits following the lowest-order ("rightmost")
one-bit in the two's complement binary representation of the specified long
value. Returns 64 if the specified value has no one-bits in its two's
complement representation, in other words if it is equal to zero.
Returns: the number of zero bits following the lowest-order ("rightmost") one-bit in the
two's complement binary representation of the specified long
value, or 64 if the value is equal to zero.
*java.lang.Long.parseLong(String)*
public static long parseLong(java.lang.String s)
throws |java.lang.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 '-' (u002D') 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 (|java.lang.Long|) method.
Note that neither the character L ('u004C') nor l ('u006C') is permitted to
appear at the end of the string as a type indicator, as would be permitted in
Java programming language source code.
s - a String containing the long representation to be parsed
Returns: the long represented by the argument in decimal.
*java.lang.Long.parseLong(String,int)*
public static long parseLong(
java.lang.String s,
int radix)
throws |java.lang.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 (|java.lang.Character|) returns a
nonnegative value), except that the first character may be an ASCII minus sign
'-' ('u002D') to indicate a negative value. The resulting long value is
returned.
Note that neither the character L ('u004C') nor l ('u006C') 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 (|java.lang.Character|) or larger than (|java.lang.Character|) .
Any character of the string is not a digit of the specified radix, except that
the first character may be a minus sign '-' ('u002d') provided that the string
is longer than length 1. The value represented by the string is not 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
s - the String containing the long representation to be parsed.
radix - the radix to be used while parsing s.
Returns: the long represented by the string argument in the specified radix.
*java.lang.Long.reverse(long)*
public static long reverse(long i)
Returns the value obtained by reversing the order of the bits in the two's
complement binary representation of the specified long value.
Returns: the value obtained by reversing order of the bits in the specified long value.
*java.lang.Long.reverseBytes(long)*
public static long reverseBytes(long i)
Returns the value obtained by reversing the order of the bytes in the two's
complement representation of the specified long value.
Returns: the value obtained by reversing the bytes in the specified long value.
*java.lang.Long.rotateLeft(long,int)*
public static long rotateLeft(
long i,
int distance)
Returns the value obtained by rotating the two's complement binary
representation of the specified long value left by the specified number of
bits. (Bits shifted out of the left hand, or high-order, side reenter on the
right, or low-order.)
Note that left rotation with a negative distance is equivalent to right
rotation: rotateLeft(val, -distance) == rotateRight(val, distance). Note also
that rotation by any multiple of 64 is a no-op, so all but the last six bits of
the rotation distance can be ignored, even if the distance is negative:
rotateLeft(val, distance) == rotateLeft(val, distance & 0x3F).
Returns: the value obtained by rotating the two's complement binary representation of
the specified long value left by the specified number of bits.
*java.lang.Long.rotateRight(long,int)*
public static long rotateRight(
long i,
int distance)
Returns the value obtained by rotating the two's complement binary
representation of the specified long value right by the specified number of
bits. (Bits shifted out of the right hand, or low-order, side reenter on the
left, or high-order.)
Note that right rotation with a negative distance is equivalent to left
rotation: rotateRight(val, -distance) == rotateLeft(val, distance). Note also
that rotation by any multiple of 64 is a no-op, so all but the last six bits of
the rotation distance can be ignored, even if the distance is negative:
rotateRight(val, distance) == rotateRight(val, distance & 0x3F).
Returns: the value obtained by rotating the two's complement binary representation of
the specified long value right by the specified number of bits.
*java.lang.Long.shortValue()*
public short shortValue()
Returns the value of this Long as a short.
*java.lang.Long.signum(long)*
public static int signum(long i)
Returns the signum function of the specified long value. (The return value is
-1 if the specified value is negative; 0 if the specified value is zero; and 1
if the specified value is positive.)
Returns: the signum function of the specified long value.
*java.lang.Long.toBinaryString(long)*
public static |java.lang.String| toBinaryString(long i)
Returns a string representation of the long argument as an unsigned integer in
base2.
The unsigned long value is the argument plus 264 if the argument is negative;
otherwise, it is equal to the argument. This value is converted to a string of
ASCII digits in binary (base2) with no extra leading 0s. If the unsigned
magnitude is zero, it is represented by a single zero character '0' ('u0030');
otherwise, the first character of the representation of the unsigned magnitude
will not be the zero character. The characters '0' ('u0030') and '1' ('u0031')
are used as binary digits.
i - a long to be converted to a string.
Returns: the string representation of the unsigned long value represented by the
argument in binary (base2).
*java.lang.Long.toHexString(long)*
public static |java.lang.String| toHexString(long i)
Returns a string representation of the long argument as an unsigned integer in
base16.
The unsigned long value is the argument plus 264 if the argument is negative;
otherwise, it is equal to the argument. This value is converted to a string of
ASCII digits in hexadecimal (base16) with no extra leading 0s. If the unsigned
magnitude is zero, it is represented by a single zero character '0' ('u0030');
otherwise, the first character of the representation of the unsigned magnitude
will not be the zero character. The following characters are used as
hexadecimal digits:
0123456789abcdef
These are the characters 'u0030' through 'u0039' and 'u0061' through 'u0066'.
If uppercase letters are desired, the (|java.lang.String|) method may be called
on the result:
Long.toHexString(n).toUpperCase()
i - a long to be converted to a string.
Returns: the string representation of the unsigned long value represented by the
argument in hexadecimal (base16).
*java.lang.Long.toOctalString(long)*
public static |java.lang.String| toOctalString(long i)
Returns a string representation of the long argument as an unsigned integer in
base8.
The unsigned long value is the argument plus 264 if the argument is negative;
otherwise, it is equal to the argument. This value is converted to a string of
ASCII digits in octal (base8) with no extra leading 0s.
If the unsigned magnitude is zero, it is represented by a single zero character
'0' ('u0030'); otherwise, the first character of the representation of the
unsigned magnitude will not be the zero character. The following characters are
used as octal digits:
01234567
These are the characters 'u0030' through 'u0037'.
i - a long to be converted to a string.
Returns: the string representation of the unsigned long value represented by the
argument in octal (base8).
*java.lang.Long.toString()*
public |java.lang.String| toString()
Returns a String object representing this Long's value. The value is converted
to signed decimal representation and returned as a string, exactly as if the
long value were given as an argument to the (|java.lang.Long|) method.
Returns: a string representation of the value of this object in base10.
*java.lang.Long.toString(long)*
public static |java.lang.String| toString(long i)
Returns a String object representing the specified long. 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
(|java.lang.Long|) method.
i - a long to be converted.
Returns: a string representation of the argument in base10.
*java.lang.Long.toString(long,int)*
public static |java.lang.String| toString(
long i,
int radix)
Returns 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 '-' ('u002d'). 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' ('u0030'); 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 'u0030' through 'u0039' and 'u0061' through 'u007a'. If 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. If
uppercase letters are desired, the (|java.lang.String|) method may be called on
the result:
Long.toString(n, 16).toUpperCase()
i - a longto be converted to a string.
radix - the radix to use in the string representation.
Returns: a string representation of the argument in the specified radix.
*java.lang.Long.valueOf(long)*
public static |java.lang.Long| valueOf(long l)
Returns a Long instance representing the specified long value. If a new Long
instance is not required, this method should generally be used in preference to
the constructor (|java.lang.Long|) , as this method is likely to yield
significantly better space and time performance by caching frequently requested
values.
l - a long value.
Returns: a Long instance representing l.
*java.lang.Long.valueOf(String)*
public static |java.lang.Long| valueOf(java.lang.String s)
throws |java.lang.NumberFormatException|
Returns a Long object holding the value of the specified String. The argument
is interpreted as representing a signed decimal long, exactly as if the
argument were given to the (|java.lang.Long|) method. The result is a Long
object that represents the integer value specified by the string.
In other words, this method returns a Long object equal to the value of:
new Long(Long.parseLong(s))
s - the string to be parsed.
Returns: a Long object holding the value represented by the string argument.
*java.lang.Long.valueOf(String,int)*
public static |java.lang.Long| valueOf(
java.lang.String s,
int radix)
throws |java.lang.NumberFormatException|
Returns a Long object holding the value extracted from the specified String
when parsed with the radix given by the second argument. The first argument is
interpreted as representing a signed long in the radix specified by the second
argument, exactly as if the arguments were given to the (|java.lang.Long|)
method. The result is a Long object that represents the long value specified by
the string.
In other words, this method returns a Long object equal to the value of:
new Long(Long.parseLong(s, radix))
s - the string to be parsed
radix - the radix to be used in interpreting s
Returns: a Long object holding the value represented by the string argument in the
specified radix.
