Module java.base
Package java.lang

Class Integer

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 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.

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).

Since:
1.0
See Also:
Serialized Form

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static int
    BYTES
    The number of bytes used to represent an int value in two's complement binary form.
    static int
    MAX_VALUE
    A constant holding the maximum value an int can have, 231-1.
    static int
    MIN_VALUE
    A constant holding the minimum value an int can have, -231.
    static int
    SIZE
    The number of bits used to represent an int value in two's complement binary form.
    static Class<Integer>
    TYPE
    The Class instance representing the primitive type int.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Integer​(int value)
    Deprecated, for removal: This API element is subject to removal in a future version.
    It is rarely appropriate to use this constructor.
    Integer​(String s)
    Deprecated, for removal: This API element is subject to removal in a future version.
    It is rarely appropriate to use this constructor.

  • Method Summary

    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 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.
    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 java.lang.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", forRemoval=true) public Integer​(int value)
      Deprecated, for removal: This API element is subject to removal in a future version.
      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", forRemoval=true) public Integer​(String s) throws NumberFormatException
      Deprecated, for removal: This API element is subject to removal in a future version.
      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()
      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:
      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:

      new Integer(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:

      new Integer(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(java.lang.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.
      Throws:
      SecurityException - for the same reasons as System.getProperty
      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, 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.
      Parameters:
      nm - property name.
      val - default value.
      Returns:
      the Integer value of the property.
      Throws:
      SecurityException - for the same reasons as System.getProperty
      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.
      Throws:
      SecurityException - for the same reasons as System.getProperty
      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

    • 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