public final class Integer

  1. Object
  2. Number
  3. Integer

ImplementsComparable<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

Fields

public static final Class<Integer> TYPE
public static final int MAX_VALUE = 2147483647The largest value of type int.
public static final int MIN_VALUE = -2147483648The smallest value of type int.

Constructors

public Integer(int value)Constructs a newly allocated Integer object that represents the primitive int argument.

Methods

public byte byteValue()Returns the value of this Integer as a byte.
public double doubleValue()Returns the value of this Integer as a double.
public boolean equals(Object obj)Compares this object to the specified object.
public float floatValue()Returns the value of this Integer as a float.
public int hashCode()Returns a hashcode for this Integer.
public int intValue()Returns the value of this Integer as an int.
public long longValue()Returns the value of this Integer as a long.
public static int parseInt(String s) throws NumberFormatExceptionParses the string argument as a signed decimal integer.
public static int parseInt(String s, int radix) throws NumberFormatExceptionParses the string argument as a signed integer in the radix specified by the second argument.
public short shortValue()Returns the value of this Integer as a short.
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.
public static String toHexString(int i)Creates a string representation of the integer argument as an unsigned integer in base 16.
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.
public String toString()Returns a String object representing this Integer’s value.
public static String toString(int i)Returns a new String object representing the specified integer.
public static String toString(int i, int radix)Creates a string representation of the first argument in the radix specified by the second argument.
public static Integer valueOf(String s) throws NumberFormatExceptionReturns a new Integer object initialized to the value of the specified String.
public static Integer valueOf(String s, int radix) throws NumberFormatExceptionReturns a new Integer object initialized to the value of the specified String.
public static Integer valueOf(int i)Returns the object instance of i
public static int signum(int i)Returns the value of the signum function for the specified integer.
public static int compare(int i1, int i2)
public int compareTo(Integer i)Compares this object to the specified object to determine their relative order.
public static int numberOfLeadingZeros(int i)

Inherited methods

Field details

TYPE

public static final Class<Integer> TYPE

MAX_VALUE

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

MIN_VALUE

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

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.

Method details

byteValue

public byte byteValue()
Returns the value of this Integer as a byte.

doubleValue

public double doubleValue()
Returns the value of this Integer as a double.

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.

floatValue

public float floatValue()
Returns the value of this Integer as a float.

hashCode

public int hashCode()
Returns a hashcode for this Integer.

intValue

public int intValue()
Returns the value of this Integer as an int.

longValue

public long longValue()
Returns the value of this Integer as a long.

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.

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

shortValue

public short shortValue()
Returns the value of this Integer as a short.

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.

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))

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))

valueOf

public static Integer valueOf(int i)
Returns the object instance of i

Parameters

i int
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 int
the integer value to check.

Returns

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

compare

public static int compare(int i1, int i2)

compareTo

public int compareTo(Integer i)
Compares this object to the specified object to determine their relative order.

Parameters

i Integer
the object to compare to this instance.

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
if another cannot be converted into something comparable to this instance.

numberOfLeadingZeros

public static int numberOfLeadingZeros(int i)