Class Integer

public static final int MAX_VALUE

The maximum value an int can represent is 2147483647 (or 2³¹ - 1).

Field Value:

2147483647

public static final int MIN_VALUE

The minimum value an int can represent is -2147483648 (or -2³¹).

Field Value:

-2147483648

public static final int SIZE

The number of bits needed to represent an int.

Field Value:

32

Since:

1.5

public static final Class TYPE

The primitive type int is represented by this Class object.

Since:

1.1

public Integer(int value)

Create an Integer object representing the value of the int argument.

Parameters:

value - the value to use

public Integer(String s)

Create an Integer object representing the value of the argument after conversion to an int.

Parameters:

s - the string to convert

Throws:

NumberFormatException - if the String does not contain an int

See Also:

valueOf(String)

public static int bitCount(int x)

Return the number of bits set in x.

Parameters:

x - value to examine

Since:

1.5

public byte byteValue()

Return the value of this Integer as a byte.

Overrides:

byteValue in interface Number

Returns:

the byte value

public static int compare(int x,
                          int y)

Compares two unboxed int values. The result is positive if the first is greater, negative if the second is greater, and 0 if the two are equal.

Parameters:

x - First value to compare.

y - Second value to compare.

Returns:

positive int if the first value is greater, negative if the second is greater, and 0 if the two are equal.

Since:

1.7

public int compareTo(Integer i)

Compare two Integers numerically by comparing their int values. The result is positive if the first is greater, negative if the second is greater, and 0 if the two are equal.

Parameters:

i - the Integer to compare

Returns:

the comparison

Since:

1.2

public static Integer decode(String str)

Convert the specified String into an Integer. The String may represent decimal, hexadecimal, or octal numbers.

The extended BNF grammar is as follows:

 DecodableString:
      ( [ - ] DecimalNumber )
    | ( [ - ] ( 0x | 0X
              | # ) HexDigit { HexDigit } )
    | ( [ - ] 0 { OctalDigit } )
 DecimalNumber:
        DecimalDigit except '0' { DecimalDigit }
 DecimalDigit:
        Character.digit(d, 10) has value 0 to 9
 OctalDigit:
        Character.digit(d, 8) has value 0 to 7
 DecimalDigit:
        Character.digit(d, 16) has value 0 to 15
 

Finally, the value must be in the range MIN_VALUE to MAX_VALUE, or an exception is thrown.

Parameters:

str - the String to interpret

Returns:

the value of the String as an Integer

Throws:

NumberFormatException - if s cannot be parsed as a int

NullPointerException - if s is null

Since:

1.2

public double doubleValue()

Return the value of this Integer as a double.

Overrides:

doubleValue in interface Number

Returns:

the double value

public boolean equals(Object obj)

Returns true if obj is an instance of Integer and represents the same int value.

Overrides:

equals in interface Object

Parameters:

obj - the object to compare

Returns:

whether these Objects are semantically equal

public float floatValue()

Return the value of this Integer as a float.

Overrides:

floatValue in interface Number

Returns:

the float value

public static Integer getInteger(String nm)

Get the specified system property as an Integer. The decode() method will be used to interpret the value of the property.

Parameters:

nm - the name of the system property

Returns:

the system property as an Integer, or null if the property is not found or cannot be decoded

Throws:

SecurityException - if accessing the system property is forbidden

See Also:

System.getProperty(String), decode(String)

public static Integer getInteger(String nm,
                                 int val)

Get the specified system property as an Integer, or use a default int value if the property is not found or is not decodable. The decode() method will be used to interpret the value of the property.

Parameters:

nm - the name of the system property

val - the default value

Returns:

the value of the system property, or the default

Throws:

SecurityException - if accessing the system property is forbidden

See Also:

System.getProperty(String), decode(String)

public static Integer getInteger(String nm,
                                 Integer def)

Get the specified system property as an Integer, or use a default Integer value if the property is not found or is not decodable. The decode() method will be used to interpret the value of the property.

Parameters:

nm - the name of the system property

def - the default value

Returns:

the value of the system property, or the default

Throws:

SecurityException - if accessing the system property is forbidden

See Also:

System.getProperty(String), decode(String)

public int hashCode()

Return a hashcode representing this Object. Integer's hash code is simply its value.

Overrides:

hashCode in interface Object

Returns:

this Object's hash code

public static int highestOneBit(int value)

Find the highest set bit in value, and return a new value with only that bit set.

Parameters:

value - the value to examine

Since:

1.5

public int intValue()

Return the value of this Integer.

Overrides:

intValue in interface Number

Returns:

the int value

public long longValue()

Return the value of this Integer as a long.

Overrides:

longValue in interface Number

Returns:

the long value

public static int lowestOneBit(int value)

Find the lowest set bit in value, and return a new value with only that bit set.

Parameters:

value - the value to examine

Since:

1.5

public static int numberOfLeadingZeros(int value)

Return the number of leading zeros in value.

Parameters:

value - the value to examine

Since:

1.5

public static int numberOfTrailingZeros(int value)

Find the number of trailing zeros in value.

Parameters:

value - the value to examine

Since:

1.5

public static int parseInt(String s)

Converts the specified String into an int. This function assumes a radix of 10.

Parameters:

s - the String to convert

Returns:

the int value of s

Throws:

NumberFormatException - if s cannot be parsed as an int

See Also:

parseInt(String,int)

public static int parseInt(String str,
                           int radix)

Converts the specified String into an int using the specified radix (base). The string must not be null or empty. It may begin with an optional '-', which will negate the answer, provided that there are also valid digits. Each digit is parsed as if by Character.digit(d, radix), and must be in the range 0 to radix - 1. Finally, the result must be within MIN_VALUE to MAX_VALUE, inclusive. Unlike Double.parseDouble, you may not have a leading '+'.

Parameters:

str - the String to convert

radix - the radix (base) to use in the conversion

Returns:

the String argument converted to int

Throws:

NumberFormatException - if s cannot be parsed as an int

public static int reverse(int val)

Reverse the bits in val.

Since:

1.5

public static int reverseBytes(int val)

Reverse the bytes in val.

Since:

1.5

public static int rotateLeft(int x,
                             int distance)

Rotate x to the left by distance bits.

Parameters:

x - the value to rotate

distance - the number of bits by which to rotate

Since:

1.5

public static int rotateRight(int x,
                              int distance)

Rotate x to the right by distance bits.

Parameters:

x - the value to rotate

distance - the number of bits by which to rotate

Since:

1.5

public short shortValue()

Return the value of this Integer as a short.

Overrides:

shortValue in interface Number

Returns:

the short value

public static int signum(int x)

Return 1 if x is positive, -1 if it is negative, and 0 if it is zero.

Parameters:

x - the value to examine

Since:

1.5

public static String toBinaryString(int i)

Converts the int to a String assuming it is unsigned in base 2.

Parameters:

i - the int to convert to String

Returns:

the String representation of the argument

public static String toHexString(int i)

Converts the int to a String assuming it is unsigned in base 16.

Parameters:

i - the int to convert to String

Returns:

the String representation of the argument

public static String toOctalString(int i)

Converts the int to a String assuming it is unsigned in base 8.

Parameters:

i - the int to convert to String

Returns:

the String representation of the argument

public String toString()

Converts the Integer value to a String and assumes a radix of 10.

Overrides:

toString in interface Object

Returns:

the String representation

public static String toString(int i)

Converts the int to a String and assumes a radix of 10.

Parameters:

i - the int to convert to String

Returns:

the String representation of the argument

See Also:

toString(int,int)

public static String toString(int num,
                              int radix)

Converts the int to a String using the specified radix (base). If the radix exceeds Character.MIN_RADIX or Character.MAX_RADIX, 10 is used instead. If the result is negative, the leading character is '-' ('\\u002D'). The remaining characters come from Character.forDigit(digit, radix) ('0'-'9','a'-'z').

Parameters:

num - the int to convert to String

radix - the radix (base) to use in the conversion

Returns:

the String representation of the argument

public static Integer valueOf(int val)

Returns an Integer object wrapping the value. In contrast to the Integer constructor, this method will cache some values. It is used by boxing conversion.

Parameters:

val - the value to wrap

Returns:

the Integer

public static Integer valueOf(String s)

Creates a new Integer object using the String, assuming a radix of 10.

Parameters:

s - the String to convert

Returns:

the new Integer

Throws:

NumberFormatException - if s cannot be parsed as an int

See Also:

Integer(String), parseInt(String)

public static Integer valueOf(String s,
                              int radix)

Creates a new Integer object using the String and specified radix (base).

Parameters:

s - the String to convert

radix - the radix (base) to convert with

Returns:

the new Integer

Throws:

NumberFormatException - if s cannot be parsed as an int

See Also:

parseInt(String,int)