java.lang
public final class Integer extends Number implements Comparable<Integer>
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
Version: 1.82, 07/09/03
| Field Summary | |
|---|---|
| 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 Class<Integer> | TYPE
The Class instance representing the primitive type
int.
|
| Constructor Summary | |
|---|---|
| Integer(int value)
Constructs a newly allocated Integer object that
represents the specified int value.
| |
| Integer(String s)
Constructs a newly allocated Integer object that
represents the int value indicated by the
String parameter. | |
| Method Summary | |
|---|---|
| byte | byteValue()
Returns the value of this Integer as a
byte. |
| int | compareTo(Integer anotherInteger)
Compares two Integer objects numerically.
|
| static Integer | decode(String nm)
Decodes a String into an Integer.
|
| double | doubleValue()
Returns the value of this Integer as a
double. |
| boolean | equals(Object obj)
Compares this object to the specified object. |
| float | floatValue()
Returns the value of this Integer as a
float. |
| 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.
|
| int | intValue()
Returns the value of this Integer as an
int. |
| long | longValue()
Returns the value of this Integer as a
long. |
| 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 | parseInt(String s)
Parses the string argument as a signed decimal integer. |
| short | shortValue()
Returns the value of this Integer as a
short. |
| 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.
|
| static String | toString(int i, int radix)
Returns a string representation of the first argument in the
radix specified by the second argument.
|
| static String | toString(int i)
Returns a String object representing the
specified integer. |
| String | toString()
Returns a String object representing this
Integer's value. |
| 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. |
| static Integer | valueOf(String s)
Returns an Integer object holding the
value of the specified String. |
| static Integer | valueOf(int i)
Returns a Integer instance representing the specified
int value.
|
int can
have, 231-1.int can
have, -231.Class instance representing the primitive type
int.
Since: JDK1.1
Integer object that
represents the specified int value.
Parameters: value the value to be represented by the
Integer object.
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.
See Also: Integer
Integer as a
byte.Integer objects numerically.
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
String into an Integer.
Accepts decimal, hexadecimal, and octal numbers numbers given
by the following grammar:
DecimalNumeral, HexDigits, and OctalDigits are defined in §3.10.1 of the Java Language Specification.
- DecodableString:
- Signopt DecimalNumeral
- Signopt
0xHexDigits- Signopt
0XHexDigits- Signopt
#HexDigits- Signopt
0OctalDigits
- Sign:
-
The sequence of characters following an (optional) negative
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: a Integer object holding the int
value represented by nm
Throws: NumberFormatException if the String does not
contain a parsable integer.
Since: 1.2
See Also: Integer
Integer as a
double.true if and only if the argument is not
null and is an Integer object that
contains the same int value as this object.
Parameters: obj the object to compare with.
Returns: true if the objects are the same;
false otherwise.
Integer as a
float.
The first argument is treated as the name of a system property.
System properties are accessible through the
java.lang.System#getProperty(java.lang.String) method. The
string value of this property is then interpreted as an integer
value and an Integer object representing this value is
returned. Details of possible numeric formats can be found with
the definition of getProperty.
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.
See Also: java.lang.System#getProperty(java.lang.String) java.lang.System#getProperty(java.lang.String, java.lang.String)
The first argument is treated as the name of a system property.
System properties are accessible through the java.lang.System#getProperty(java.lang.String) method. The
string value of this property is then interpreted as an integer
value and an Integer object representing this value is
returned. Details of possible numeric formats can be found with
the definition of getProperty.
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))
to avoid the unnecessary allocation of anInteger result = getInteger(nm, null); return (result == null) ? new Integer(val) : result;
Integer
object when the default value is not needed.
Parameters: nm property name. val default value.
Returns: the Integer value of the property.
See Also: java.lang.System#getProperty(java.lang.String) java.lang.System#getProperty(java.lang.String, java.lang.String)
Integer.decode method,
and an Integer object representing this value is
returned.
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
Integer with radix 16.
0 followed by another character, it is parsed as an
octal integer exactly as by the method
Integer with radix 8.
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.
See Also: java.lang.System#getProperty(java.lang.String) java.lang.System#getProperty(java.lang.String, java.lang.String) Integer
Integer.
Returns: a hash code value for this object, equal to the
primitive int value represented by this
Integer object.
Integer as an
int.Integer as a
long.'-' ('\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:
null or is a string of
length zero.
'-' ('\u002D') provided that the
string is longer than length 1.
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
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.
'-'
('\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
Integer 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.
Integer as a
short.
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.
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: JDK1.0.2
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 hexadecimal (base 16) 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:
These are the characters0123456789abcdef
'\u0030' through
'\u0039' and '\u0061' through
'\u0066'. If uppercase letters are
desired, the 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: JDK1.0.2
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 octal (base 8) 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 octal
digits:
These are the characters01234567
'\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: JDK1.0.2
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:
These are0123456789abcdefghijklmnopqrstuvwxyz
'\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 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.
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 Integer method.
Parameters: i an integer to be converted.
Returns: a string representation of the argument in base 10.
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 Integer method.
Returns: a string representation of the value of this object in base 10.
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 Integer
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.
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 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.
Parameters: i a int value.
Returns: a Integer instance representing i.
Since: 1.5