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Summary: Nested Field Constr Method Detail: Field Constr Method

java.lang

Class Integer

public final class Integer extends Number implements Comparable<Integer>

Instances of class Integer represent primitive int values. Additionally, this class provides various helper functions and variables related to ints.

Since: 1.0

UNKNOWN: updated to 1.5

Field Summary
static intMAX_VALUE
The maximum value an int can represent is 2147483647 (or 231 - 1).
static intMIN_VALUE
The minimum value an int can represent is -2147483648 (or -231).
static intSIZE
The number of bits needed to represent an int.
static Class<Integer>TYPE
The primitive type int is represented by this Class object.
Constructor Summary
Integer(int value)
Create an Integer object representing the value of the int argument.
Integer(String s)
Create an Integer object representing the value of the argument after conversion to an int.
Method Summary
static intbitCount(int x)
Return the number of bits set in x.
bytebyteValue()
Return the value of this Integer as a byte.
intcompareTo(Integer i)
Compare two Integers numerically by comparing their int values.
static Integerdecode(String str)
Convert the specified String into an Integer.
doubledoubleValue()
Return the value of this Integer as a double.
booleanequals(Object obj)
Returns true if obj is an instance of Integer and represents the same int value.
floatfloatValue()
Return the value of this Integer as a float.
static IntegergetInteger(String nm)
Get the specified system property as an Integer.
static IntegergetInteger(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.
static IntegergetInteger(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.
inthashCode()
Return a hashcode representing this Object.
static inthighestOneBit(int value)
Find the highest set bit in value, and return a new value with only that bit set.
intintValue()
Return the value of this Integer.
longlongValue()
Return the value of this Integer as a long.
static intlowestOneBit(int value)
Find the lowest set bit in value, and return a new value with only that bit set.
static intnumberOfLeadingZeros(int value)
Return the number of leading zeros in value.
static intnumberOfTrailingZeros(int value)
Find the number of trailing zeros in value.
static intparseInt(String str, int radix)
Converts the specified String into an int using the specified radix (base).
static intparseInt(String s)
Converts the specified String into an int.
static intreverse(int val)
Reverse the bits in val.
static intreverseBytes(int val)
Reverse the bytes in val.
static introtateLeft(int x, int distance)
Rotate x to the left by distance bits.
static introtateRight(int x, int distance)
Rotate x to the right by distance bits.
shortshortValue()
Return the value of this Integer as a short.
static intsignum(int x)
Return 1 if x is positive, -1 if it is negative, and 0 if it is zero.
static StringtoBinaryString(int i)
Converts the int to a String assuming it is unsigned in base 2.
static StringtoHexString(int i)
Converts the int to a String assuming it is unsigned in base 16.
static StringtoOctalString(int i)
Converts the int to a String assuming it is unsigned in base 8.
static StringtoString(int num, int radix)
Converts the int to a String using the specified radix (base).
static StringtoString(int i)
Converts the int to a String and assumes a radix of 10.
StringtoString()
Converts the Integer value to a String and assumes a radix of 10.
static IntegervalueOf(String s, int radix)
Creates a new Integer object using the String and specified radix (base).
static IntegervalueOf(String s)
Creates a new Integer object using the String, assuming a radix of 10.
static IntegervalueOf(int val)
Returns an Integer object wrapping the value.

Field Detail

MAX_VALUE

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

MIN_VALUE

public static final int MIN_VALUE
The minimum value an int can represent is -2147483648 (or -231).

SIZE

public static final int SIZE
The number of bits needed to represent an int.

Since: 1.5

TYPE

public static final Class<Integer> TYPE
The primitive type int is represented by this Class object.

Since: 1.1

Constructor Detail

Integer

public Integer(int value)
Create an Integer object representing the value of the int argument.

Parameters: value the value to use

Integer

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

Method Detail

bitCount

public static int bitCount(int x)
Return the number of bits set in x.

Parameters: x value to examine

Since: 1.5

byteValue

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

Returns: the byte value

compareTo

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

decode

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

doubleValue

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

Returns: the double value

equals

public boolean equals(Object obj)
Returns true if obj is an instance of Integer and represents the same int value.

Parameters: obj the object to compare

Returns: whether these Objects are semantically equal

floatValue

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

Returns: the float value

getInteger

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: getProperty decode

getInteger

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: getProperty decode

getInteger

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: getProperty decode

hashCode

public int hashCode()
Return a hashcode representing this Object. Integer's hash code is simply its value.

Returns: this Object's hash code

highestOneBit

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

intValue

public int intValue()
Return the value of this Integer.

Returns: the int value

longValue

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

Returns: the long value

lowestOneBit

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

numberOfLeadingZeros

public static int numberOfLeadingZeros(int value)
Return the number of leading zeros in value.

Parameters: value the value to examine

Since: 1.5

numberOfTrailingZeros

public static int numberOfTrailingZeros(int value)
Find the number of trailing zeros in value.

Parameters: value the value to examine

Since: 1.5

parseInt

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

parseInt

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: Integer

reverse

public static int reverse(int val)
Reverse the bits in val.

Since: 1.5

reverseBytes

public static int reverseBytes(int val)
Reverse the bytes in val.

Since: 1.5

rotateLeft

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

rotateRight

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

shortValue

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

Returns: the short value

signum

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

toBinaryString

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

toHexString

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

toOctalString

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

toString

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

toString

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: Integer

toString

public String toString()
Converts the Integer value to a String and assumes a radix of 10.

Returns: the String representation

valueOf

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: Integer

valueOf

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 parseInt

valueOf

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

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Summary: Nested Field Constr Method Detail: Field Constr Method