*java.lang.Integer* *Integer* The Integer class wraps a value of the primitive t
public final class Integer
extends |java.lang.Number|
implements |java.lang.Comparable|
|java.lang.Integer_Description|
|java.lang.Integer_Fields|
|java.lang.Integer_Constructors|
|java.lang.Integer_Methods|
================================================================================
*java.lang.Integer_Fields*
|int_java.lang.Integer.MAX_VALUE|
|int_java.lang.Integer.MIN_VALUE|
|int_java.lang.Integer.SIZE|
|java.lang.Class<java.lang.Integer>_java.lang.Integer.TYPE|
*java.lang.Integer_Constructors*
|java.lang.Integer(int)|Constructs a newly allocated Integer object that repre
|java.lang.Integer(String)|Constructs a newly allocated Integer object that re
*java.lang.Integer_Methods*
|java.lang.Integer.bitCount(int)|Returns the number of one-bits in the two's co
|java.lang.Integer.byteValue()|Returns the value of this Integer as a byte.
|java.lang.Integer.compareTo(Integer)|Compares two Integer objects numerically.
|java.lang.Integer.decode(String)|Decodes a String into an Integer.
|java.lang.Integer.doubleValue()|Returns the value of this Integer as a double
|java.lang.Integer.equals(Object)|Compares this object to the specified object.
|java.lang.Integer.floatValue()|Returns the value of this Integer as a float.
|java.lang.Integer.getInteger(String)|Determines the integer value of the syste
|java.lang.Integer.getInteger(String,int)|Determines the integer value of the s
|java.lang.Integer.getInteger(String,Integer)|Returns the integer value of the
|java.lang.Integer.hashCode()|Returns a hash code for this Integer.
|java.lang.Integer.highestOneBit(int)|Returns an int value with at most a singl
|java.lang.Integer.intValue()|Returns the value of this Integer as an int.
|java.lang.Integer.longValue()|Returns the value of this Integer as a long.
|java.lang.Integer.lowestOneBit(int)|Returns an int value with at most a single
|java.lang.Integer.numberOfLeadingZeros(int)|Returns the number of zero bits pr
|java.lang.Integer.numberOfTrailingZeros(int)|Returns the number of zero bits f
|java.lang.Integer.parseInt(String)|Parses the string argument as a signed deci
|java.lang.Integer.parseInt(String,int)|Parses the string argument as a signed
|java.lang.Integer.reverse(int)|Returns the value obtained by reversing the ord
|java.lang.Integer.reverseBytes(int)|Returns the value obtained by reversing th
|java.lang.Integer.rotateLeft(int,int)|Returns the value obtained by rotating t
|java.lang.Integer.rotateRight(int,int)|Returns the value obtained by rotating
|java.lang.Integer.shortValue()|Returns the value of this Integer as a short.
|java.lang.Integer.signum(int)|Returns the signum function of the specified int
|java.lang.Integer.toBinaryString(int)|Returns a string representation of the i
|java.lang.Integer.toHexString(int)|Returns a string representation of the inte
|java.lang.Integer.toOctalString(int)|Returns a string representation of the in
|java.lang.Integer.toString()|Returns a String object representing this Intege
|java.lang.Integer.toString(int)|Returns a String object representing the spec
|java.lang.Integer.toString(int,int)|Returns a string representation of the fir
|java.lang.Integer.valueOf(int)|Returns a Integer instance representing the spe
|java.lang.Integer.valueOf(String)|Returns an Integer object holding the value
|java.lang.Integer.valueOf(String,int)|Returns an Integer object holding the va
*java.lang.Integer_Description*
The Integer class wraps a value of the primitive type int in an object. An
object of type Integer contains a single field whose type is int.
In addition, this class provides several methods for converting an int to a
String and a String to an int, as well as other constants and methods useful
when dealing with an int.
Implementation note: The implementations of the "bit twiddling" methods (such
as highestOneBit(|java.lang.Integer|) and
numberOfTrailingZeros(|java.lang.Integer|) ) are based on material from Henry
S. Warren, Jr.'s Hacker's Delight, (Addison Wesley, 2002).
*int_java.lang.Integer.MAX_VALUE*
A constant holding the maximum value an int can have, 231-1.
*int_java.lang.Integer.MIN_VALUE*
A constant holding the minimum value an int can have, -231.
*int_java.lang.Integer.SIZE*
The number of bits used to represent an int value in two's complement binary
form.
*java.lang.Class<java.lang.Integer>_java.lang.Integer.TYPE*
The Class instance representing the primitive type int.
*java.lang.Integer(int)*
public Integer(int value)
Constructs a newly allocated Integer object that represents the specified int
value.
value - the value to be represented by the Integer object.
*java.lang.Integer(String)*
public Integer(java.lang.String s)
throws |java.lang.NumberFormatException|
Constructs a newly allocated Integer object that represents the int value
indicated by the String parameter. The string is converted to an int value in
exactly the manner used by the parseInt method for radix 10.
s - the String to be converted to an Integer.
*java.lang.Integer.bitCount(int)*
public static int bitCount(int i)
Returns the number of one-bits in the two's complement binary representation of
the specified int 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 int value.
*java.lang.Integer.byteValue()*
public byte byteValue()
Returns the value of this Integer as a byte.
*java.lang.Integer.compareTo(Integer)*
public int compareTo(java.lang.Integer anotherInteger)
Compares two Integer objects numerically.
anotherInteger - the Integer to be compared.
Returns: the value 0 if this Integer is equal to the argument Integer; a value less than
0 if this Integer is numerically less than the argument Integer;
and a value greater than 0 if this Integer is numerically greater
than the argument Integer (signed comparison).
*java.lang.Integer.decode(String)*
public static |java.lang.Integer| decode(java.lang.String nm)
throws |java.lang.NumberFormatException|
Decodes a String into an Integer. 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 Integer.parseInt
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 Integer object holding the int value represented by nm
*java.lang.Integer.doubleValue()*
public double doubleValue()
Returns the value of this Integer as a double.
*java.lang.Integer.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 an Integer object that contains the same int
value as this object.
obj - the object to compare with.
Returns: true if the objects are the same; false otherwise.
*java.lang.Integer.floatValue()*
public float floatValue()
Returns the value of this Integer as a float.
*java.lang.Integer.getInteger(String)*
public static |java.lang.Integer| getInteger(java.lang.String nm)
Determines the integer 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 an integer value and an Integer
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 an Integer object equal to the value of:
getInteger(nm, null)
nm - property name.
Returns: the Integer value of the property.
*java.lang.Integer.getInteger(String,int)*
public static |java.lang.Integer| getInteger(
java.lang.String nm,
int val)
Determines the integer 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 an integer value and an Integer
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. An Integer 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 an Integer object equal to the value of:
getInteger(nm, new Integer(val))
but in practice it may be implemented in a manner such as:
Integer result = getInteger(nm, null); return (result == null) ? new
Integer(val) : result;
to avoid the unnecessary allocation of an Integer object when the default value
is not needed.
nm - property name.
val - default value.
Returns: the Integer value of the property.
*java.lang.Integer.getInteger(String,Integer)*
public static |java.lang.Integer| getInteger(
java.lang.String nm,
java.lang.Integer val)
Returns the integer 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 an integer value, as per the
Integer.decode method, and an Integer 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 by the method (|java.lang.Integer|) 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.Integer|) with radix 8. Otherwise, the property value is parsed as
a decimal integer exactly as by the method (|java.lang.Integer|) with radix 10.
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 Integer value of the property.
*java.lang.Integer.hashCode()*
public int hashCode()
Returns a hash code for this Integer.
Returns: a hash code value for this object, equal to the primitive int value represented
by this Integer object.
*java.lang.Integer.highestOneBit(int)*
public static int highestOneBit(int i)
Returns an int value with at most a single one-bit, in the position of the
highest-order ("leftmost") one-bit in the specified int 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: an int 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.Integer.intValue()*
public int intValue()
Returns the value of this Integer as an int.
*java.lang.Integer.longValue()*
public long longValue()
Returns the value of this Integer as a long.
*java.lang.Integer.lowestOneBit(int)*
public static int lowestOneBit(int i)
Returns an int value with at most a single one-bit, in the position of the
lowest-order ("rightmost") one-bit in the specified int 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: an int 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.Integer.numberOfLeadingZeros(int)*
public static int numberOfLeadingZeros(int i)
Returns the number of zero bits preceding the highest-order ("leftmost")
one-bit in the two's complement binary representation of the specified int
value. Returns 32 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 int values x:
floor(log2(x)) = 31 - numberOfLeadingZeros(x) ceil(log2(x)) = 32 -
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 int value,
or 32 if the value is equal to zero.
*java.lang.Integer.numberOfTrailingZeros(int)*
public static int numberOfTrailingZeros(int i)
Returns the number of zero bits following the lowest-order ("rightmost")
one-bit in the two's complement binary representation of the specified int
value. Returns 32 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 int value,
or 32 if the value is equal to zero.
*java.lang.Integer.parseInt(String)*
public static int parseInt(java.lang.String s)
throws |java.lang.NumberFormatException|
Parses the string argument as a signed decimal integer. 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
integer value is returned, exactly as if the argument and the radix 10 were
given as arguments to the (|java.lang.Integer|) method.
s - a String containing the int representation to be parsed
Returns: the integer value represented by the argument in decimal.
*java.lang.Integer.parseInt(String,int)*
public static int parseInt(
java.lang.String s,
int radix)
throws |java.lang.NumberFormatException|
Parses the string argument as a signed integer 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 integer value is
returned.
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 int.
Examples:
parseInt("0", 10) returns 0 parseInt("473", 10) returns 473 parseInt("-0", 10)
returns 0 parseInt("-FF", 16) returns -255 parseInt("1100110", 2) returns 102
parseInt("2147483647", 10) returns 2147483647 parseInt("-2147483648", 10)
returns -2147483648 parseInt("2147483648", 10) throws a NumberFormatException
parseInt("99", 8) throws a NumberFormatException parseInt("Kona", 10) throws a
NumberFormatException parseInt("Kona", 27) returns 411787
s - the String containing the integer representation to be parsed
radix - the radix to be used while parsing s.
Returns: the integer represented by the string argument in the specified radix.
*java.lang.Integer.reverse(int)*
public static int reverse(int i)
Returns the value obtained by reversing the order of the bits in the two's
complement binary representation of the specified int value.
Returns: the value obtained by reversing order of the bits in the specified int value.
*java.lang.Integer.reverseBytes(int)*
public static int reverseBytes(int i)
Returns the value obtained by reversing the order of the bytes in the two's
complement representation of the specified int value.
Returns: the value obtained by reversing the bytes in the specified int value.
*java.lang.Integer.rotateLeft(int,int)*
public static int rotateLeft(
int i,
int distance)
Returns the value obtained by rotating the two's complement binary
representation of the specified int 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 32 is a no-op, so all but the last five bits
of the rotation distance can be ignored, even if the distance is negative:
rotateLeft(val, distance) == rotateLeft(val, distance & 0x1F).
Returns: the value obtained by rotating the two's complement binary representation of
the specified int value left by the specified number of bits.
*java.lang.Integer.rotateRight(int,int)*
public static int rotateRight(
int i,
int distance)
Returns the value obtained by rotating the two's complement binary
representation of the specified int 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 32 is a no-op, so all but the last five bits
of the rotation distance can be ignored, even if the distance is negative:
rotateRight(val, distance) == rotateRight(val, distance & 0x1F).
Returns: the value obtained by rotating the two's complement binary representation of
the specified int value right by the specified number of bits.
*java.lang.Integer.shortValue()*
public short shortValue()
Returns the value of this Integer as a short.
*java.lang.Integer.signum(int)*
public static int signum(int i)
Returns the signum function of the specified int 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 int value.
*java.lang.Integer.toBinaryString(int)*
public static |java.lang.String| toBinaryString(int i)
Returns a string representation of the integer argument as an unsigned integer
in base2.
The unsigned integer value is the argument plus 232 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 - an integer to be converted to a string.
Returns: the string representation of the unsigned integer value represented by the
argument in binary (base2).
*java.lang.Integer.toHexString(int)*
public static |java.lang.String| toHexString(int i)
Returns a string representation of the integer argument as an unsigned integer
in base16.
The unsigned integer value is the argument plus 232 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:
Integer.toHexString(n).toUpperCase()
i - an integer to be converted to a string.
Returns: the string representation of the unsigned integer value represented by the
argument in hexadecimal (base16).
*java.lang.Integer.toOctalString(int)*
public static |java.lang.String| toOctalString(int i)
Returns a string representation of the integer argument as an unsigned integer
in base8.
The unsigned integer value is the argument plus 232 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 - an integer to be converted to a string.
Returns: the string representation of the unsigned integer value represented by the
argument in octal (base8).
*java.lang.Integer.toString()*
public |java.lang.String| toString()
Returns a String object representing this Integer's value. The value is
converted to signed decimal representation and returned as a string, exactly as
if the integer value were given as an argument to the (|java.lang.Integer|)
method.
Returns: a string representation of the value of this object in base10.
*java.lang.Integer.toString(int)*
public static |java.lang.String| toString(int i)
Returns a 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 radix 10 were given as arguments to the
(|java.lang.Integer|) method.
i - an integer to be converted.
Returns: a string representation of the argument in base10.
*java.lang.Integer.toString(int,int)*
public static |java.lang.String| toString(
int 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 character '-' ('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:
Integer.toString(n, 16).toUpperCase()
i - an integer to 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.Integer.valueOf(int)*
public static |java.lang.Integer| valueOf(int i)
Returns a Integer instance representing the specified int value. If a new
Integer instance is not required, this method should generally be used in
preference to the constructor (|java.lang.Integer|) , as this method is likely
to yield significantly better space and time performance by caching frequently
requested values.
i - an int value.
Returns: a Integer instance representing i.
*java.lang.Integer.valueOf(String)*
public static |java.lang.Integer| valueOf(java.lang.String s)
throws |java.lang.NumberFormatException|
Returns an Integer object holding the value of the specified String. The
argument is interpreted as representing a signed decimal integer, exactly as if
the argument were given to the (|java.lang.Integer|) method. The result is an
Integer object that represents the integer value specified by the string.
In other words, this method returns an Integer object equal to the value of:
new Integer(Integer.parseInt(s))
s - the string to be parsed.
Returns: an Integer object holding the value represented by the string argument.
*java.lang.Integer.valueOf(String,int)*
public static |java.lang.Integer| valueOf(
java.lang.String s,
int radix)
throws |java.lang.NumberFormatException|
Returns an Integer 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 integer in the radix specified by the
second argument, exactly as if the arguments were given to the
(|java.lang.Integer|) method. The result is an Integer object that represents
the integer value specified by the string.
In other words, this method returns an Integer object equal to the value of:
new Integer(Integer.parseInt(s, radix))
s - the string to be parsed.
radix - the radix to be used in interpreting s
Returns: an Integer object holding the value represented by the string argument in the
specified radix.
