Viewing: docs.oracle.com

Contents

Description
Field Summary
Constructor Summary
Method Summary
Field Details
1. MIN_VALUE
2. MAX_VALUE
3. TYPE
4. SIZE
5. BYTES
Constructor Details
1. Integer(int)
2. Integer(String)
Method Details

Hide sidebar

[Hide sidebar]

[Show sidebar] Show sidebar

java.lang.Object

java.lang.Number

java.lang.Integer

All Implemented Interfaces:: Serializable, Comparable<Integer>, Constable, ConstantDesc

public final class Integer extends Number implements Comparable<Integer>, Constable, ConstantDesc

The Integer class is the wrapper class for values of the primitive type int. 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.

This is a value-based class; programmers should treat instances that are equal as interchangeable and should not use instances for synchronization, or unpredictable behavior may occur. For example, in a future release, synchronization may fail.

Implementation note: The implementations of the "bit twiddling" methods (such as highestOneBit and numberOfTrailingZeros) are based on material from Henry S. Warren, Jr.'s Hacker's Delight, (Addison Wesley, 2002) and Hacker's Delight, Second Edition, (Pearson Education, 2013).

Since:

1.0

See Also:

Field Summary

Fields

Modifier and Type

Field

Description

static final int

BYTES

The number of bytes used to represent an int value in two's complement binary form.

static final int

MAX_VALUE

A constant holding the maximum value an int can have, 231-1.

static final int

MIN_VALUE

A constant holding the minimum value an int can have, -231.

static final int

SIZE

The number of bits used to represent an int value in two's complement binary form.

static final Class<Integer>

TYPE

The Class instance representing the primitive type int.
Constructor Summary

Constructors

Constructor

Description

Integer(int value)

Deprecated.
It is rarely appropriate to use this constructor.

Integer(String s)

Deprecated.
It is rarely appropriate to use this constructor.
Method Summary

All MethodsStatic MethodsInstance MethodsConcrete Methods

Modifier and Type

Method

Description

static int

bitCount(int i)

Returns the number of one-bits in the two's complement binary representation of the specified int value.

byte

byteValue()

Returns the value of this Integer as a byte after a narrowing primitive conversion.

static int

compare(int x, int y)

Compares two int values numerically.

int

compareTo(Integer anotherInteger)

Compares two Integer objects numerically.

static int

compareUnsigned(int x, int y)

Compares two int values numerically treating the values as unsigned.

static int

compress(int i, int mask)

Returns the value obtained by compressing the bits of the specified int value, i, in accordance with the specified bit mask.

static Integer

decode(String nm)

Decodes a String into an Integer.

Optional<Integer>

describeConstable()

Returns an Optional containing the nominal descriptor for this instance, which is the instance itself.

static int

divideUnsigned(int dividend, int divisor)

Returns the unsigned quotient of dividing the first argument by the second where each argument and the result is interpreted as an unsigned value.

double

doubleValue()

Returns the value of this Integer as a double after a widening primitive conversion.

boolean

equals(Object obj)

Compares this object to the specified object.

static int

expand(int i, int mask)

Returns the value obtained by expanding the bits of the specified int value, i, in accordance with the specified bit mask.

float

floatValue()

Returns the value of this Integer as a float after a widening primitive conversion.

static Integer

getInteger(String nm)

Determines the integer value of the system property with the specified name.

static Integer

getInteger(String nm, int val)

Determines the integer value of the system property with the specified name.

static Integer

getInteger(String nm, Integer val)

Returns the integer value of the system property with the specified name.

int

hashCode()

Returns a hash code for this Integer.

static int

hashCode(int value)

Returns a hash code for an int value; compatible with Integer.hashCode().

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.

int

intValue()

Returns the value of this Integer as an int.

long

longValue()

Returns the value of this Integer as a long after a widening primitive conversion.

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.

static int

max(int a, int b)

Returns the greater of two int values as if by calling Math.max.

static int

min(int a, int b)

Returns the smaller of two int values as if by calling Math.min.

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.

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.

static int

parseInt(CharSequence s, int beginIndex, int endIndex, int radix)

Parses the CharSequence argument as a signed int in the specified radix, beginning at the specified beginIndex and extending to endIndex - 1.

static int

parseInt(String s)

Parses the string argument as a signed decimal integer.

static int

parseInt(String s, int radix)

Parses the string argument as a signed integer in the radix specified by the second argument.

static int

parseUnsignedInt(CharSequence s, int beginIndex, int endIndex, int radix)

Parses the CharSequence argument as an unsigned int in the specified radix, beginning at the specified beginIndex and extending to endIndex - 1.

static int

parseUnsignedInt(String s)

Parses the string argument as an unsigned decimal integer.

static int

parseUnsignedInt(String s, int radix)

Parses the string argument as an unsigned integer in the radix specified by the second argument.

static int

remainderUnsigned(int dividend, int divisor)

Returns the unsigned remainder from dividing the first argument by the second where each argument and the result is interpreted as an unsigned value.

Integer

resolveConstantDesc(MethodHandles.Lookup lookup)

Resolves this instance as a ConstantDesc, the result of which is the instance itself.

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.

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.

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.

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.

short

shortValue()

Returns the value of this Integer as a short after a narrowing primitive conversion.

static int

signum(int i)

Returns the signum function of the specified int value.

static int

sum(int a, int b)

Adds two integers together as per the + operator.

static String

toBinaryString(int i)

Returns a string representation of the integer argument as an unsigned integer in base 2.

static String

toHexString(int i)

Returns a string representation of the integer argument as an unsigned integer in base 16.

static String

toOctalString(int i)

Returns a string representation of the integer argument as an unsigned integer in base 8.

String

toString()

Returns a String object representing this Integer's value.

static String

toString(int i)

Returns a String object representing the specified integer.

static String

toString(int i, int radix)

Returns a string representation of the first argument in the radix specified by the second argument.

static long

toUnsignedLong(int x)

Converts the argument to a long by an unsigned conversion.

static String

toUnsignedString(int i)

Returns a string representation of the argument as an unsigned decimal value.

static String

toUnsignedString(int i, int radix)

Returns a string representation of the first argument as an unsigned integer value in the radix specified by the second argument.

static Integer

valueOf(int i)

Returns an Integer instance representing the specified int value.

static Integer

valueOf(String s)

Returns an Integer object holding the value of the specified String.

static Integer

valueOf(String s, int radix)

Returns an Integer object holding the value extracted from the specified String when parsed with the radix given by the second argument.

Methods declared in class Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details
- MIN_VALUE
  @Native public static final int MIN_VALUE
  
  A constant holding the minimum value an int can have, -231.
  See Also:
  Constant Field Values
- MAX_VALUE
  @Native public static final int MAX_VALUE
  
  A constant holding the maximum value an int can have, 231-1.
  See Also:
  Constant Field Values
- TYPE
  
  public static final Class<Integer> TYPE
  
  The Class instance representing the primitive type int.
  
  Since:
  
  1.1
- SIZE
  @Native public static final int SIZE
  
  The number of bits used to represent an int value in two's complement binary form.
  Since:
  
  1.5
  
  See Also:
  Constant Field Values
- BYTES
  public static final int BYTES
  
  The number of bytes used to represent an int value in two's complement binary form.
  Since:
  
  1.8
  
  See Also:
  Constant Field Values
Constructor Details
- Integer
  
  @Deprecated(since="9") public Integer(int value)
  
  Deprecated.
  It is rarely appropriate to use this constructor. The static factory valueOf(int) is generally a better choice, as it is likely to yield significantly better space and time performance.
  
  Constructs a newly allocated Integer object that represents the specified int value.
  
  Parameters:
  
  value - the value to be represented by the Integer object.
- Integer
  
  @Deprecated(since="9") public Integer(String s) throws NumberFormatException
  
  Deprecated.
  It is rarely appropriate to use this constructor. Use parseInt(String) to convert a string to a int primitive, or use valueOf(String) to convert a string to an Integer object.
  
  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.
  
  Parameters:
  
  s - the String to be converted to an Integer.
  
  Throws:
  
  NumberFormatException - if the String does not contain a parsable integer.
Method Details
- toString
  public static 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 String.toUpperCase() method may be called on the result:
  Integer.toString(n, 16).toUpperCase()
  Parameters:
  
  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.
  
  See Also:
  Character.MAX_RADIX
  
  Character.MIN_RADIX
- toUnsignedString
  public static String toUnsignedString(int i, int radix)
  
  Returns a string representation of the first argument as an unsigned integer value 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.
  Note that since the first argument is treated as an unsigned value, no leading sign character is printed.
  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 behavior of radixes and the characters used as digits are the same as toString.
  Parameters:
  
  i - an integer to be converted to an unsigned string.
  
  radix - the radix to use in the string representation.
  
  Returns:
  
  an unsigned string representation of the argument in the specified radix.
  
  Since:
  
  1.8
  
  See Also:
  toString(int, int)
- toHexString
  public static String toHexString(int i)
  
  Returns a string representation of the integer argument as an unsigned integer in base 16.
  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 (base 16) with no extra leading 0s.
  The value of the argument can be recovered from the returned string s by calling Integer.parseUnsignedInt(s, 16).
  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 String.toUpperCase() method may be called on the result:
  Integer.toHexString(n).toUpperCase()
  API Note:
  
  The HexFormat class provides formatting and parsing of byte arrays and primitives to return a string or adding to an Appendable. HexFormat formats and parses uppercase or lowercase hexadecimal characters, with leading zeros and for byte arrays includes for each byte a delimiter, prefix, and suffix.
  
  Parameters:
  
  i - an integer to be converted to a string.
  
  Returns:
  
  the string representation of the unsigned integer value represented by the argument in hexadecimal (base 16).
  
  Since:
  
  1.0.2
  
  See Also:
  HexFormat
  
  parseUnsignedInt(String, int)
  
  toUnsignedString(int, int)
- toOctalString
  public static String toOctalString(int i)
  
  Returns a string representation of the integer argument as an unsigned integer in base 8.
  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 (base 8) with no extra leading 0s.
  The value of the argument can be recovered from the returned string s by calling Integer.parseUnsignedInt(s, 8).
  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'.
  Parameters:
  
  i - an integer to be converted to a string.
  
  Returns:
  
  the string representation of the unsigned integer value represented by the argument in octal (base 8).
  
  Since:
  
  1.0.2
  
  See Also:
  parseUnsignedInt(String, int)
  
  toUnsignedString(int, int)
- toBinaryString
  public static String toBinaryString(int i)
  
  Returns a string representation of the integer argument as an unsigned integer in base 2.
  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 (base 2) with no extra leading 0s.
  The value of the argument can be recovered from the returned string s by calling Integer.parseUnsignedInt(s, 2).
  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.
  Parameters:
  
  i - an integer to be converted to a string.
  
  Returns:
  
  the string representation of the unsigned integer value represented by the argument in binary (base 2).
  
  Since:
  
  1.0.2
  
  See Also:
  parseUnsignedInt(String, int)
  
  toUnsignedString(int, int)
- toString
  
  public static 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 toString(int, int) method.
  
  Parameters:
  
  i - an integer to be converted.
  
  Returns:
  
  a string representation of the argument in base 10.
- toUnsignedString
  public static String toUnsignedString(int i)
  
  Returns a string representation of the argument as an unsigned decimal value. The argument is converted to unsigned decimal representation and returned as a string exactly as if the argument and radix 10 were given as arguments to the toUnsignedString(int, int) method.
  Parameters:
  
  i - an integer to be converted to an unsigned string.
  
  Returns:
  
  an unsigned string representation of the argument.
  
  Since:
  
  1.8
  
  See Also:
  toUnsignedString(int, int)
- parseInt
  public static int parseInt(String s, int radix) throws 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 Character.digit(char, int) returns a nonnegative value), except that the first character may be an ASCII minus sign '-' ('\u002D') to indicate a negative value or an ASCII plus sign '+' ('\u002B') to indicate a positive 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 Character.MIN_RADIX or larger than Character.MAX_RADIX.
  - Any character of the string is not a digit of the specified radix, except that the first character may be a minus sign '-' ('\u002D') or plus sign '+' ('\u002B') 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("+42", 10) returns 42 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
  Parameters:
  
  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.
  
  Throws:
  
  NumberFormatException - if the String does not contain a parsable int.
- parseInt
  
  public static int parseInt(CharSequence s, int beginIndex, int endIndex, int radix) throws NumberFormatException
  
  Parses the CharSequence argument as a signed int in the specified radix, beginning at the specified beginIndex and extending to endIndex - 1.
  The method does not take steps to guard against the CharSequence being mutated while parsing.
  
  Parameters:
  
  s - the CharSequence containing the int representation to be parsed
  
  beginIndex - the beginning index, inclusive.
  
  endIndex - the ending index, exclusive.
  
  radix - the radix to be used while parsing s.
  
  Returns:
  
  the signed int represented by the subsequence in the specified radix.
  
  Throws:
  
  NullPointerException - if s is null.
  
  IndexOutOfBoundsException - if beginIndex is negative, or if beginIndex is greater than endIndex or if endIndex is greater than s.length().
  
  NumberFormatException - if the CharSequence does not contain a parsable int in the specified radix, or if radix is either smaller than Character.MIN_RADIX or larger than Character.MAX_RADIX.
  
  Since:
  
  9
- parseInt
  
  public static int parseInt(String s) throws 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 or an ASCII plus sign '+' ('\u002B') to indicate a positive value. The resulting integer value is returned, exactly as if the argument and the radix 10 were given as arguments to the parseInt(java.lang.String, int) method.
  
  Parameters:
  
  s - a String containing the int representation to be parsed
  
  Returns:
  
  the integer value represented by the argument in decimal.
  
  Throws:
  
  NumberFormatException - if the string does not contain a parsable integer.
- parseUnsignedInt
  public static int parseUnsignedInt(String s, int radix) throws NumberFormatException
  Parses the string argument as an unsigned integer in the radix specified by the second argument. An unsigned integer maps the values usually associated with negative numbers to positive numbers larger than MAX_VALUE. The characters in the string must all be digits of the specified radix (as determined by whether Character.digit(char, int) returns a nonnegative value), except that the first character may be an ASCII plus sign '+' ('\u002B'). 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 Character.MIN_RADIX or larger than Character.MAX_RADIX.
  - Any character of the string is not a digit of the specified radix, except that the first character may be a plus sign '+' ('\u002B') provided that the string is longer than length 1.
  - The value represented by the string is larger than the largest unsigned int, 232-1.
  Parameters:
  
  s - the String containing the unsigned 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.
  
  Throws:
  
  NumberFormatException - if the String does not contain a parsable int.
  
  Since:
  
  1.8
- parseUnsignedInt
  
  public static int parseUnsignedInt(CharSequence s, int beginIndex, int endIndex, int radix) throws NumberFormatException
  
  Parses the CharSequence argument as an unsigned int in the specified radix, beginning at the specified beginIndex and extending to endIndex - 1.
  The method does not take steps to guard against the CharSequence being mutated while parsing.
  
  Parameters:
  
  s - the CharSequence containing the unsigned int representation to be parsed
  
  beginIndex - the beginning index, inclusive.
  
  endIndex - the ending index, exclusive.
  
  radix - the radix to be used while parsing s.
  
  Returns:
  
  the unsigned int represented by the subsequence in the specified radix.
  
  Throws:
  
  NullPointerException - if s is null.
  
  IndexOutOfBoundsException - if beginIndex is negative, or if beginIndex is greater than endIndex or if endIndex is greater than s.length().
  
  NumberFormatException - if the CharSequence does not contain a parsable unsigned int in the specified radix, or if radix is either smaller than Character.MIN_RADIX or larger than Character.MAX_RADIX.
  
  Since:
  
  9
- parseUnsignedInt
  
  public static int parseUnsignedInt(String s) throws NumberFormatException
  
  Parses the string argument as an unsigned decimal integer. The characters in the string must all be decimal digits, except that the first character may be an ASCII plus sign '+' ('\u002B'). The resulting integer value is returned, exactly as if the argument and the radix 10 were given as arguments to the parseUnsignedInt(java.lang.String, int) method.
  
  Parameters:
  
  s - a String containing the unsigned int representation to be parsed
  
  Returns:
  
  the unsigned integer value represented by the argument in decimal.
  
  Throws:
  
  NumberFormatException - if the string does not contain a parsable unsigned integer.
  
  Since:
  
  1.8
- valueOf
  
  public static Integer valueOf(String s, int radix) throws 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 parseInt(java.lang.String, int) 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:
  Integer.valueOf(Integer.parseInt(s, radix))
  
  Parameters:
  
  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.
  
  Throws:
  
  NumberFormatException - if the String does not contain a parsable int.
- valueOf
  
  public static Integer valueOf(String s) throws 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 parseInt(java.lang.String) 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:
  Integer.valueOf(Integer.parseInt(s))
  
  Parameters:
  
  s - the string to be parsed.
  
  Returns:
  
  an Integer object holding the value represented by the string argument.
  
  Throws:
  
  NumberFormatException - if the string cannot be parsed as an integer.
- valueOf
  
  public static Integer valueOf(int i)
  
  Returns an 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 Integer(int), as this method is likely to yield significantly better space and time performance by caching frequently requested values. This method will always cache values in the range -128 to 127, inclusive, and may cache other values outside of this range.
  
  Parameters:
  
  i - an int value.
  
  Returns:
  
  an Integer instance representing i.
  
  Since:
  
  1.5
- byteValue
  
  public byte byteValue()
  
  Returns the value of this Integer as a byte after a narrowing primitive conversion.
  
  Overrides:
  
  byteValue in class Number
  
  Returns:
  
  the numeric value represented by this object after conversion to type byte.
  
  See Java Language Specification:
  
  5.1.3 Narrowing Primitive Conversion
- shortValue
  
  public short shortValue()
  
  Returns the value of this Integer as a short after a narrowing primitive conversion.
  
  Overrides:
  
  shortValue in class Number
  
  Returns:
  
  the numeric value represented by this object after conversion to type short.
  
  See Java Language Specification:
  
  5.1.3 Narrowing Primitive Conversion
- intValue
  
  public int intValue()
  
  Returns the value of this Integer as an int.
  
  Specified by:
  
  intValue in class Number
  
  Returns:
  
  the numeric value represented by this object after conversion to type int.
- longValue
  public long longValue()
  
  Returns the value of this Integer as a long after a widening primitive conversion.
  Specified by:
  
  longValue in class Number
  
  Returns:
  
  the numeric value represented by this object after conversion to type long.
  
  See Java Language Specification:
  
  5.1.2 Widening Primitive Conversion
  
  See Also:
  toUnsignedLong(int)
- floatValue
  
  public float floatValue()
  
  Returns the value of this Integer as a float after a widening primitive conversion.
  
  Specified by:
  
  floatValue in class Number
  
  Returns:
  
  the numeric value represented by this object after conversion to type float.
  
  See Java Language Specification:
  
  5.1.2 Widening Primitive Conversion
- doubleValue
  
  public double doubleValue()
  
  Returns the value of this Integer as a double after a widening primitive conversion.
  
  Specified by:
  
  doubleValue in class Number
  
  Returns:
  
  the numeric value represented by this object after conversion to type double.
  
  See Java Language Specification:
  
  5.1.2 Widening Primitive Conversion
- toString
  
  public 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 toString(int) method.
  
  Overrides:
  
  toString in class Object
  
  Returns:
  
  a string representation of the value of this object in base 10.
- hashCode
  public int hashCode()
  
  Returns a hash code for this Integer.
  Overrides:
  
  hashCode in class Object
  
  Returns:
  
  a hash code value for this object, equal to the primitive int value represented by this Integer object.
  
  See Also:
  Object.equals(java.lang.Object)
  
  System.identityHashCode(Object)
- hashCode
  
  public static int hashCode(int value)
  
  Returns a hash code for an int value; compatible with Integer.hashCode().
  
  Parameters:
  
  value - the value to hash
  
  Returns:
  
  a hash code value for an int value.
  
  Since:
  
  1.8
- equals
  public boolean equals(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.
  Overrides:
  
  equals in class Object
  
  Parameters:
  
  obj - the object to compare with.
  
  Returns:
  
  true if the objects are the same; false otherwise.
  
  See Also:
  Object.hashCode()
  
  HashMap
- getInteger
  public static Integer getInteger(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 System.getProperty(java.lang.String) method. The string value of this property is then interpreted as an integer value using the grammar supported by decode and an Integer object representing this value is returned.
  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)
  Parameters:
  
  nm - property name.
  
  Returns:
  
  the Integer value of the property.
  
  See Also:
  System.getProperty(java.lang.String)
  
  System.getProperty(java.lang.String, java.lang.String)
- getInteger
  public static Integer getInteger(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 System.getProperty(java.lang.String) method. The string value of this property is then interpreted as an integer value using the grammar supported by decode and an Integer object representing this value is returned.
  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, Integer.valueOf(val))
  but in practice it may be implemented in a manner such as:
  Integer result = getInteger(nm, null); return (result == null) ? Integer.valueOf(val) : result;
  to avoid the unnecessary allocation of an Integer object when the default value is not needed.
  Parameters:
  
  nm - property name.
  
  val - default value.
  
  Returns:
  
  the Integer value of the property.
  
  See Also:
  System.getProperty(java.lang.String)
  
  System.getProperty(java.lang.String, java.lang.String)
- getInteger
  public static Integer getInteger(String nm, 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 System.getProperty(java.lang.String) method. The string value of this property is then interpreted as an integer value, as per the decode method, and an Integer object representing this value is returned; in summary:
  - 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 valueOf(java.lang.String, int) 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 valueOf(java.lang.String, int) with radix 8.
  - Otherwise, the property value is parsed as a decimal integer exactly as by the method valueOf(java.lang.String, int) 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.
  Parameters:
  
  nm - property name.
  
  val - default value.
  
  Returns:
  
  the Integer value of the property.
  
  See Also:
  System.getProperty(java.lang.String)
  
  System.getProperty(java.lang.String, java.lang.String)
- decode
  public static Integer decode(String nm) throws 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 as defined in section 3.10.1 of The Java Language Specification, except that underscores are not accepted between digits.
  The sequence of characters following an optional 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 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.
  Parameters:
  
  nm - the String to decode.
  
  Returns:
  
  an Integer object holding the int value represented by nm
  
  Throws:
  
  NumberFormatException - if the String does not contain a parsable integer.
  
  See Also:
  parseInt(java.lang.String, int)
- compareTo
  
  public int compareTo(Integer anotherInteger)
  
  Compares two Integer objects numerically.
  
  Specified by:
  
  compareTo in interface Comparable<Integer>
  
  Parameters:
  
  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).
  
  Since:
  
  1.2
- compare
  public static int compare(int x, int y)
  Compares two int values numerically. The value returned is identical to what would be returned by:
```
   Integer.valueOf(x).compareTo(Integer.valueOf(y))
```
  Parameters:
  
  x - the first int to compare
  
  y - the second int to compare
  
  Returns:
  
  the value 0 if x == y; a value less than 0 if x < y; and a value greater than 0 if x > y
  
  Since:
  
  1.7
- compareUnsigned
  
  public static int compareUnsigned(int x, int y)
  
  Compares two int values numerically treating the values as unsigned.
  
  Parameters:
  
  x - the first int to compare
  
  y - the second int to compare
  
  Returns:
  
  the value 0 if x == y; a value less than 0 if x < y as unsigned values; and a value greater than 0 if x > y as unsigned values
  
  Since:
  
  1.8
- toUnsignedLong
  
  public static long toUnsignedLong(int x)
  
  Converts the argument to a long by an unsigned conversion. In an unsigned conversion to a long, the high-order 32 bits of the long are zero and the low-order 32 bits are equal to the bits of the integer argument. Consequently, zero and positive int values are mapped to a numerically equal long value and negative int values are mapped to a long value equal to the input plus 232.
  
  Parameters:
  
  x - the value to convert to an unsigned long
  
  Returns:
  
  the argument converted to long by an unsigned conversion
  
  Since:
  
  1.8
- divideUnsigned
  public static int divideUnsigned(int dividend, int divisor)
  
  Returns the unsigned quotient of dividing the first argument by the second where each argument and the result is interpreted as an unsigned value.
  Note that in two's complement arithmetic, the three other basic arithmetic operations of add, subtract, and multiply are bit-wise identical if the two operands are regarded as both being signed or both being unsigned. Therefore separate addUnsigned, etc. methods are not provided.
  Parameters:
  
  dividend - the value to be divided
  
  divisor - the value doing the dividing
  
  Returns:
  
  the unsigned quotient of the first argument divided by the second argument
  
  Since:
  
  1.8
  
  See Also:
  remainderUnsigned(int, int)
- remainderUnsigned
  public static int remainderUnsigned(int dividend, int divisor)
  
  Returns the unsigned remainder from dividing the first argument by the second where each argument and the result is interpreted as an unsigned value.
  Parameters:
  
  dividend - the value to be divided
  
  divisor - the value doing the dividing
  
  Returns:
  
  the unsigned remainder of the first argument divided by the second argument
  
  Since:
  
  1.8
  
  See Also:
  divideUnsigned(int, int)
- highestOneBit
  
  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.
  
  Parameters:
  
  i - the value whose highest one bit is to be computed
  
  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.
  
  Since:
  
  1.5
- lowestOneBit
  
  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.
  
  Parameters:
  
  i - the value whose lowest one bit is to be computed
  
  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.
  
  Since:
  
  1.5
- numberOfLeadingZeros
  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)
  Parameters:
  
  i - the value whose number of leading zeros is to be computed
  
  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.
  
  Since:
  
  1.5
- numberOfTrailingZeros
  
  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.
  
  Parameters:
  
  i - the value whose number of trailing zeros is to be computed
  
  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.
  
  Since:
  
  1.5
- bitCount
  
  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.
  
  Parameters:
  
  i - the value whose bits are to be counted
  
  Returns:
  
  the number of one-bits in the two's complement binary representation of the specified int value.
  
  Since:
  
  1.5
- rotateLeft
  
  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).
  
  Parameters:
  
  i - the value whose bits are to be rotated left
  
  distance - the number of bit positions to rotate left
  
  Returns:
  
  the value obtained by rotating the two's complement binary representation of the specified int value left by the specified number of bits.
  
  Since:
  
  1.5
- rotateRight
  
  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).
  
  Parameters:
  
  i - the value whose bits are to be rotated right
  
  distance - the number of bit positions to rotate right
  
  Returns:
  
  the value obtained by rotating the two's complement binary representation of the specified int value right by the specified number of bits.
  
  Since:
  
  1.5
- reverse
  
  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.
  
  Parameters:
  
  i - the value to be reversed
  
  Returns:
  
  the value obtained by reversing order of the bits in the specified int value.
  
  Since:
  
  1.5
- compress
  public static int compress(int i, int mask)
  
  Returns the value obtained by compressing the bits of the specified int value, i, in accordance with the specified bit mask.
  For each one-bit value mb of the mask, from least significant to most significant, the bit value of i at the same bit location as mb is assigned to the compressed value contiguously starting from the least significant bit location. All the upper remaining bits of the compressed value are set to zero.
  API Note:
  Consider the simple case of compressing the digits of a hexadecimal value:
  Copy [Copy snippet]
  // Compressing drink to food compress(0xCAFEBABE, 0xFF00FFF0) == 0xCABAB
  
  Starting from the least significant hexadecimal digit at position 0 from the right, the mask 0xFF00FFF0 selects hexadecimal digits at positions 1, 2, 3, 6 and 7 of 0xCAFEBABE. The selected digits occur in the resulting compressed value contiguously from digit position 0 in the same order.
  The following identities all return true and are helpful to understand the behaviour of compress:
  Copy [Copy snippet]
  // Returns 1 if the bit at position n is one compress(x, 1 << n) == (x >> n & 1) // Logical shift right compress(x, -1 << n) == x >>> n // Any bits not covered by the mask are ignored compress(x, m) == compress(x & m, m) // Compressing a value by itself compress(m, m) == (m == -1 || m == 0) ? m : (1 << bitCount(m)) - 1 // Expanding then compressing with the same mask compress(expand(x, m), m) == x & compress(m, m)
  
  The Sheep And Goats (SAG) operation (see Hacker's Delight, Second Edition, section 7.7) can be implemented as follows:
  Copy [Copy snippet]
  int compressLeft(int i, int mask) { // This implementation follows the description in Hacker's Delight which // is informative. A more optimal implementation is: // Integer.compress(i, mask) << -Integer.bitCount(mask) return Integer.reverse( Integer.compress(Integer.reverse(i), Integer.reverse(mask))); } int sag(int i, int mask) { return compressLeft(i, mask) | Integer.compress(i, ~mask); } // Separate the sheep from the goats sag(0xCAFEBABE, 0xFF00FFF0) == 0xCABABFEE
  Parameters:
  
  i - the value whose bits are to be compressed
  
  mask - the bit mask
  
  Returns:
  
  the compressed value
  
  Since:
  
  19
  
  See Also:
  expand(int, int)
- expand
  public static int expand(int i, int mask)
  
  Returns the value obtained by expanding the bits of the specified int value, i, in accordance with the specified bit mask.
  For each one-bit value mb of the mask, from least significant to most significant, the next contiguous bit value of i starting at the least significant bit is assigned to the expanded value at the same bit location as mb. All other remaining bits of the expanded value are set to zero.
  API Note:
  Consider the simple case of expanding the digits of a hexadecimal value:
  Copy [Copy snippet]
  expand(0x0000CABAB, 0xFF00FFF0) == 0xCA00BAB0
  
  Starting from the least significant hexadecimal digit at position 0 from the right, the mask 0xFF00FFF0 selects the first five hexadecimal digits of 0x0000CABAB. The selected digits occur in the resulting expanded value in order at positions 1, 2, 3, 6, and 7.
  The following identities all return true and are helpful to understand the behaviour of expand:
  Copy [Copy snippet]
  // Logically shift right the bit at position 0 expand(x, 1 << n) == (x & 1) << n // Logically shift right expand(x, -1 << n) == x << n // Expanding all bits returns the mask expand(-1, m) == m // Any bits not covered by the mask are ignored expand(x, m) == expand(x, m) & m // Compressing then expanding with the same mask expand(compress(x, m), m) == x & m
  
  The select operation for determining the position of the one-bit with index n in a int value can be implemented as follows:
  Copy [Copy snippet]
  int select(int i, int n) { // the one-bit in i (the mask) with index n int nthBit = Integer.expand(1 << n, i); // the bit position of the one-bit with index n return Integer.numberOfTrailingZeros(nthBit); } // The one-bit with index 0 is at bit position 1 select(0b10101010_10101010, 0) == 1 // The one-bit with index 3 is at bit position 7 select(0b10101010_10101010, 3) == 7
  Parameters:
  
  i - the value whose bits are to be expanded
  
  mask - the bit mask
  
  Returns:
  
  the expanded value
  
  Since:
  
  19
  
  See Also:
  compress(int, int)
- signum
  
  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.)
  
  Parameters:
  
  i - the value whose signum is to be computed
  
  Returns:
  
  the signum function of the specified int value.
  
  Since:
  
  1.5
- reverseBytes
  
  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.
  
  Parameters:
  
  i - the value whose bytes are to be reversed
  
  Returns:
  
  the value obtained by reversing the bytes in the specified int value.
  
  Since:
  
  1.5
- sum
  public static int sum(int a, int b)
  
  Adds two integers together as per the + operator.
  Parameters:
  
  a - the first operand
  
  b - the second operand
  
  Returns:
  
  the sum of a and b
  
  Since:
  
  1.8
  
  See Also:
  BinaryOperator
- max
  public static int max(int a, int b)
  
  Returns the greater of two int values as if by calling Math.max.
  Parameters:
  
  a - the first operand
  
  b - the second operand
  
  Returns:
  
  the greater of a and b
  
  Since:
  
  1.8
  
  See Also:
  BinaryOperator
- min
  public static int min(int a, int b)
  
  Returns the smaller of two int values as if by calling Math.min.
  Parameters:
  
  a - the first operand
  
  b - the second operand
  
  Returns:
  
  the smaller of a and b
  
  Since:
  
  1.8
  
  See Also:
  BinaryOperator
- describeConstable
  
  public Optional<Integer> describeConstable()
  
  Returns an Optional containing the nominal descriptor for this instance, which is the instance itself.
  
  Specified by:
  
  describeConstable in interface Constable
  
  Returns:
  
  an Optional describing the Integer instance
  
  Since:
  
  12
- resolveConstantDesc
  
  public Integer resolveConstantDesc(MethodHandles.Lookup lookup)
  
  Resolves this instance as a ConstantDesc, the result of which is the instance itself.
  
  Specified by:
  
  resolveConstantDesc in interface ConstantDesc
  
  Parameters:
  
  lookup - ignored
  
  Returns:
  
  the Integer instance
  
  Since:
  
  12

Report a bug or suggest an enhancement
For further API reference and developer documentation see the Java SE Documentation, which contains more detailed, developer-targeted descriptions with conceptual overviews, definitions of terms, workarounds, and working code examples. Other versions.
Java is a trademark or registered trademark of Oracle and/or its affiliates in the US and other countries.
Copyright © 1993, 2026, Oracle and/or its affiliates, 500 Oracle Parkway, Redwood Shores, CA 94065 USA.
All rights reserved. Use is subject to license terms and the documentation redistribution policy.

Class Integer

Field Summary

Constructor Summary

Method Summary

Methods declared in class Object

Field Details

MIN_VALUE

MAX_VALUE

TYPE

SIZE

BYTES

Constructor Details

Integer

Integer

Method Details

toString

toUnsignedString

toHexString

toOctalString

toBinaryString

toString

toUnsignedString

parseInt

parseInt

parseInt

parseUnsignedInt

parseUnsignedInt

parseUnsignedInt

valueOf

valueOf

valueOf

byteValue

shortValue

intValue

longValue

floatValue

doubleValue

toString

hashCode

hashCode

equals

getInteger

getInteger

getInteger

decode

compareTo

compare

compareUnsigned

toUnsignedLong

divideUnsigned

remainderUnsigned

highestOneBit

lowestOneBit

numberOfLeadingZeros

numberOfTrailingZeros

bitCount

rotateLeft

rotateRight

reverse

compress

expand

signum

reverseBytes

sum

max

min

describeConstable

resolveConstantDesc