Class Integer

java.lang.Object
java.lang.Number
java.lang.Integer
All Implemented Interfaces:
Comparable<Integer>
public final class Integer extends Number implements Comparable<Integer>
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. Since: JDK1.0, CLDC 1.0

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    BYTES
    The size of an int in bytes.
    static final int
    MAX_VALUE
    The largest value of type int.
    static final int
    MIN_VALUE
    The smallest value of type int.
    static final int
    SIZE
    The size of an int in bits.
    static final Class<Integer>
    TYPE
     

  • Constructor Summary

    Constructors
    Constructor
    Description
    Integer(int value)
    Constructs a newly allocated Integer object that represents the primitive int argument.
    Integer(String s)
    Deprecated.

  • Method Summary

    Modifier and Type
    Method
    Description
    static int
    bitCount(int i)
    The number of one bits.
    byte
    byteValue()
    Returns the value of this Integer as a byte.
    static int
    compare(int i1, int i2)
     
    int
    compareTo(Integer i)
    Compares this object to the specified object to determine their relative order.
    static int
    compareUnsigned(int x, int y)
    Compares the two as unsigned values.
    static int
    compress(int i, int mask)
    The bits of i selected by mask, packed to the low end.
    static Integer
    decode(String nm)
    Decodes a decimal, 0x, 0X, # or leading-zero octal int, with an optional sign.
    static int
    divideUnsigned(int dividend, int divisor)
    The unsigned quotient.
    double
    doubleValue()
    Returns the value of this Integer as a double.
    boolean
    equals(Object obj)
    Compares this object to the specified object.
    static int
    expand(int i, int mask)
    The low bits of i spread to the positions of the one bits of mask.
    float
    floatValue()
    Returns the value of this Integer as a float.
    static Integer
    getInteger(String nm)
    The system property nm as an Integer, or null.
    static Integer
    getInteger(String nm, int val)
    The system property nm as an Integer, or val.
    static Integer
    getInteger(String nm, Integer val)
    The system property nm decoded as an Integer, or val when it is unset or not a number.
    int
    hashCode()
    Returns a hashcode for this Integer.
    static int
    hashCode(int value)
    The value itself.
    static int
    highestOneBit(int i)
    The highest one bit alone, or 0.
    int
    intValue()
    Returns the value of this Integer as an int.
    long
    longValue()
    Returns the value of this Integer as a long.
    static int
    lowestOneBit(int i)
    The lowest one bit alone, or 0.
    static int
    max(int a, int b)
     
    static int
    min(int a, int b)
     
    static int
    numberOfLeadingZeros(int i)
     
    static int
    numberOfTrailingZeros(int i)
    The number of zero bits below the lowest one bit; 32 for zero.
    static int
    parseInt(CharSequence s, int beginIndex, int endIndex, int radix)
    Parses s from beginIndex to endIndex as a signed int.
    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 s from beginIndex to endIndex as an unsigned int.
    static int
    parseUnsignedInt(String s)
    Parses an unsigned decimal int.
    static int
    parseUnsignedInt(String s, int radix)
    Parses an unsigned int in radix.
    static int
    remainderUnsigned(int dividend, int divisor)
    The unsigned remainder.
    static int
    reverse(int i)
    The bits in reverse order.
    static int
    reverseBytes(int i)
    The bytes in reverse order.
    static int
    rotateLeft(int i, int distance)
     
    static int
    rotateRight(int i, int distance)
    The bits rotated right by distance.
    short
    shortValue()
    Returns the value of this Integer as a short.
    static int
    signum(int i)
    Returns the value of the signum function for the specified integer.
    static int
    sum(int a, int b)
     
    static String
    toBinaryString(int i)
    Creates a string representation of the integer argument as an unsigned integer in base 2.
    static String
    toHexString(int i)
    Creates a string representation of the integer argument as an unsigned integer in base 16.
    static String
    toOctalString(int i)
    Creates 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 new String object representing the specified integer.
    static String
    toString(int i, int radix)
    Creates a string representation of the first argument in the radix specified by the second argument.
    static long
    toUnsignedLong(int x)
    The value as an unsigned long.
    static String
    toUnsignedString(int i)
    The value as an unsigned decimal string.
    static String
    toUnsignedString(int i, int radix)
    The value as an unsigned string in radix.
    static Integer
    valueOf(int i)
    Returns the object instance of i
    static Integer
    valueOf(String s)
    Returns a new Integer object initialized to the value of the specified String.
    static Integer
    valueOf(String s, int radix)
    Returns a new Integer object initialized to the value of the specified String.

    Methods inherited from class Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

  • Field Details

    • TYPE

      public static final Class<Integer> TYPE

    • MAX_VALUE

      public static final int MAX_VALUE
      The largest value of type int. The constant value of this field is 2147483647. See Also:Constant Field Values
      See Also:

    • MIN_VALUE

      public static final int MIN_VALUE
      The smallest value of type int. The constant value of this field is -2147483648. See Also:Constant Field Values
      See Also:

    • BYTES

      public static final int BYTES
      The size of an int in bytes.
      See Also:

    • SIZE

      public static final int SIZE
      The size of an int in bits.
      See Also:

  • Constructor Details

    • Integer

      public Integer(int value)
      Constructs a newly allocated Integer object that represents the primitive int argument. value - the value to be represented by the Integer.

    • Integer

      @Deprecated public Integer(String s) throws NumberFormatException
      Deprecated.
      An Integer of parseInt(s).
      Throws:
      NumberFormatException

  • Method Details

    • byteValue

      public byte byteValue()
      Returns the value of this Integer as a byte.
      Overrides:
      byteValue in class Number

    • doubleValue

      public double doubleValue()
      Returns the value of this Integer as a double.
      Specified by:
      doubleValue in class Number

    • 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

    • floatValue

      public float floatValue()
      Returns the value of this Integer as a float.
      Specified by:
      floatValue in class Number

    • hashCode

      public int hashCode()
      Returns a hashcode for this Integer.
      Overrides:
      hashCode in class Object

    • intValue

      public int intValue()
      Returns the value of this Integer as an int.
      Specified by:
      intValue in class Number

    • longValue

      public long longValue()
      Returns the value of this Integer as a long.
      Specified by:
      longValue in class Number

    • 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. The resulting integer value is returned, exactly as if the argument and the radix 10 were given as arguments to the method.
      Throws:
      NumberFormatException

    • 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 returns a nonnegative value), except that the first character may be an ASCII minus sign '-' (' u002d') to indicate a negative value. The resulting integer value is returned. An exception of type NumberFormatException is thrown if any of the following situations occurs: The first argument is null or is a string of length zero. The radix is either smaller than 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') provided that the string is longer than length 1. The integer value represented by the string is not a value of type int. Examples: parseInt("0", 10) returns 0 parseInt("473", 10) returns 473 parseInt("-0", 10) returns 0 parseInt("-FF", 16) returns -255 parseInt("1100110", 2) returns 102 parseInt("2147483647", 10) returns 2147483647 parseInt("-2147483648", 10) returns -2147483648 parseInt("2147483648", 10) throws a NumberFormatException parseInt("99", 8) throws a NumberFormatException parseInt("Kona", 10) throws a NumberFormatException parseInt("Kona", 27) returns 411787
      Throws:
      NumberFormatException

    • shortValue

      public short shortValue()
      Returns the value of this Integer as a short.
      Overrides:
      shortValue in class Number

    • toBinaryString

      public static String toBinaryString(int i)
      Creates a string representation of the integer argument as an unsigned integer in base 2. The unsigned integer value is the argument plus 232if the argument is negative; otherwise it is equal to the argument. This value is converted to a string of ASCII digits in binary (base2) with no extra leading 0s. If the unsigned magnitude is zero, it is represented by a single zero character '0' ('u0030'); otherwise, the first character of the representation of the unsigned magnitude will not be the zero character. The characters '0' ('u0030') and '1' ('u0031') are used as binary digits.

    • toHexString

      public static String toHexString(int i)
      Creates 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 (base16) with no extra leading 0s. If the unsigned magnitude is zero, it is represented by a single zero character '0' ('u0030'); otherwise, the first character of the representation of the unsigned magnitude will not be the zero character. The following characters are used as hexadecimal digits: 0123456789abcdef These are the characters ' u0030' through ' u0039' and 'u\0039' through ' u0066'.

    • toOctalString

      public static String toOctalString(int i)
      Creates 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 (base8) with no extra leading 0s. If the unsigned magnitude is zero, it is represented by a single zero character '0' ('u0030'); otherwise, the first character of the representation of the unsigned magnitude will not be the zero character. The octal digits are: 01234567 These are the characters ' u0030' through ' u0037'.

    • 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 method.
      Overrides:
      toString in class Object

    • toString

      public static String toString(int i)
      Returns a new String object representing the specified integer. The argument is converted to signed decimal representation and returned as a string, exactly as if the argument and radix 10 were given as arguments to the method.

    • toString

      public static String toString(int i, int radix)
      Creates a string representation of the first argument in the radix specified by the second argument. If the radix is smaller than Character.MIN_RADIX or larger than Character.MAX_RADIX, then the radix 10 is used instead. If the first argument is negative, the first element of the result is the ASCII minus 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 the radix is N, then the first N of these characters are used as radix-N digits in the order shown. Thus, the digits for hexadecimal (radix 16) are 0123456789abcdef.

    • valueOf

      public static Integer valueOf(String s) throws NumberFormatException
      Returns a new Integer object initialized to 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 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))
      Throws:
      NumberFormatException

    • valueOf

      public static Integer valueOf(String s, int radix) throws NumberFormatException
      Returns a new Integer object initialized to the value of the specified String. 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 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))
      Throws:
      NumberFormatException

    • valueOf

      public static Integer valueOf(int i)

      Returns the object instance of i

      Parameters
      • i: the primitive
      Returns

      object instance

    • signum

      public static int signum(int i)

      Returns the value of the signum function for the specified integer.

      Parameters
      • i: the integer value to check.
      Returns
      Returns:

      -1 if i is negative, 1 if i is positive, 0 if i is zero.

      Since

      1.5

    • compare

      public static int compare(int i1, int i2)

    • compareTo

      public int compareTo(Integer i)
      Description copied from interface: Comparable

      Compares this object to the specified object to determine their relative order.

      Parameters
      • another: the object to compare to this instance.
      Returns
      Specified by:
      compareTo in interface Comparable<Integer>
      Returns:

      a negative integer if this instance is less than another; a positive integer if this instance is greater than another; 0 if this instance has the same order as another.

      Throws
      • ClassCastException: @throws ClassCastException if another cannot be converted into something comparable to this instance.

    • numberOfLeadingZeros

      public static int numberOfLeadingZeros(int i)

    • rotateLeft

      public static int rotateLeft(int i, int distance)

    • sum

      public static int sum(int a, int b)

    • max

      public static int max(int a, int b)

    • min

      public static int min(int a, int b)

    • hashCode

      public static int hashCode(int value)
      The value itself.

    • bitCount

      public static int bitCount(int i)
      The number of one bits.

    • highestOneBit

      public static int highestOneBit(int i)
      The highest one bit alone, or 0.

    • lowestOneBit

      public static int lowestOneBit(int i)
      The lowest one bit alone, or 0.

    • numberOfTrailingZeros

      public static int numberOfTrailingZeros(int i)
      The number of zero bits below the lowest one bit; 32 for zero.

    • reverse

      public static int reverse(int i)
      The bits in reverse order.

    • reverseBytes

      public static int reverseBytes(int i)
      The bytes in reverse order.

    • rotateRight

      public static int rotateRight(int i, int distance)
      The bits rotated right by distance.

    • compareUnsigned

      public static int compareUnsigned(int x, int y)
      Compares the two as unsigned values.

    • toUnsignedLong

      public static long toUnsignedLong(int x)
      The value as an unsigned long.

    • divideUnsigned

      public static int divideUnsigned(int dividend, int divisor)
      The unsigned quotient.

    • remainderUnsigned

      public static int remainderUnsigned(int dividend, int divisor)
      The unsigned remainder.

    • toUnsignedString

      public static String toUnsignedString(int i)
      The value as an unsigned decimal string.

    • toUnsignedString

      public static String toUnsignedString(int i, int radix)
      The value as an unsigned string in radix.

    • parseUnsignedInt

      public static int parseUnsignedInt(String s) throws NumberFormatException
      Parses an unsigned decimal int.
      Throws:
      NumberFormatException

    • parseUnsignedInt

      public static int parseUnsignedInt(String s, int radix) throws NumberFormatException
      Parses an unsigned int in radix.
      Throws:
      NumberFormatException

    • parseInt

      public static int parseInt(CharSequence s, int beginIndex, int endIndex, int radix) throws NumberFormatException
      Parses s from beginIndex to endIndex as a signed int.
      Throws:
      NumberFormatException

    • parseUnsignedInt

      public static int parseUnsignedInt(CharSequence s, int beginIndex, int endIndex, int radix) throws NumberFormatException
      Parses s from beginIndex to endIndex as an unsigned int.
      Throws:
      NumberFormatException

    • decode

      public static Integer decode(String nm) throws NumberFormatException
      Decodes a decimal, 0x, 0X, # or leading-zero octal int, with an optional sign.
      Throws:
      NumberFormatException

    • getInteger

      public static Integer getInteger(String nm)
      The system property nm as an Integer, or null.

    • getInteger

      public static Integer getInteger(String nm, int val)
      The system property nm as an Integer, or val.

    • getInteger

      public static Integer getInteger(String nm, Integer val)
      The system property nm decoded as an Integer, or val when it is unset or not a number.

    • compress

      public static int compress(int i, int mask)
      The bits of i selected by mask, packed to the low end.

    • expand

      public static int expand(int i, int mask)
      The low bits of i spread to the positions of the one bits of mask.