
Java Platform 1.2 

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SUMMARY: INNER  FIELD  CONSTR  METHOD  DETAIL: FIELD  CONSTR  METHOD 
java.lang.Object  +java.lang.Number  +java.lang.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
.
Field Summary  
static int 
MAX_VALUE
The largest value of type int . 
static int 
MIN_VALUE
The smallest value of type int . 
static Class 
TYPE
The Class object representing the primitive type int. 
Constructor Summary  
Integer(int value)
Constructs a newly allocated Integer object that
represents the primitive int argument. 

Integer(String s)
Constructs a newly allocated Integer object that
represents the value represented by the string. 
Method Summary  
byte 
byteValue()
Returns the value of this Integer as a byte. 
int 
compareTo(Integer anotherInteger)
Compares two Integers numerically. 
int 
compareTo(Object o)
Compares this Integer to another Object. 
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 hashcode 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)
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. 
short 
shortValue()
Returns the value of this Integer as a short. 
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 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 java.lang.Object 
clone,
finalize,
getClass,
notify,
notifyAll,
wait,
wait,
wait 
Field Detail 
public static final int MIN_VALUE
int
. The constant
value of this field is 2147483648.public static final int MAX_VALUE
int
. The constant
value of this field is 2147483647.public static final Class TYPE
Constructor Detail 
public Integer(int value)
Integer
object that
represents the primitive int
argument.value
 the value to be represented by the Integer
.public Integer(String s) throws NumberFormatException
Integer
object that
represents the value represented by the string. The string is
converted to an int in exactly the manner used by the
parseInt method for radix 10.s
 the String
to be converted to an
Integer
.String
does not
contain a parsable integer.parseInt(java.lang.String, int)
Method Detail 
public static String toString(int i, int radix)
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 are '\u0030' through '\u0039' and '\u0061' through '\u007a'. If the radix is N, then the first N of these characters are used as radixN digets in the order shown. Thus, the digits for hexadecimal (radix 16) are 0123456789abcdef. If uppercase letters are desired, the0123456789abcdefghijklmnopqrstuvwxyz
String.toUpperCase()
method
may be called on the result:
Integer.toString(n, 16).toUpperCase()
i
 an integer.radix
 the radix.Character.MAX_RADIX
,
Character.MIN_RADIX
public static String toHexString(int i)
The unsigned integer value is the argument plus 2^{32} 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 0
s. 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 characters '\u0030' through '\u0039' and 'u\0039' through '\u0066'. If the uppercase letters are desired, the0123456789abcdef
String.toUpperCase()
method may be called on the result:
Long.toHexString(n).toUpperCase()
i
 an integer.public static String toOctalString(int i)
The unsigned integer value is the argument plus 2^{32} 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 0
s.
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:
These are the characters '\u0030' through '\u0037'.01234567
i
 an integerpublic static String toBinaryString(int i)
The unsigned integer value is the argument plus 2^{32}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 0
s.
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.
i
 an integer.public static String toString(int i)
toString(int, int)
method.i
 an integer to be converted.public static int parseInt(String s, int radix) throws NumberFormatException
Character.digit(char, int)
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:
Character.MIN_RADIX
or
larger than Character.MAX_RADIX
.
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
s
 the String
containing the integer.radix
 the radix to be used.public static int parseInt(String s) throws NumberFormatException
''
('\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
parseInt(java.lang.String, int)
method.s
 a string.public static Integer valueOf(String s, int radix) throws NumberFormatException
parseInt(java.lang.String, int)
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))
s
 the string to be parsed.radix
 the radix of the integer represented by string
sInteger
initialized to the
value represented by the string argument in the specified
radix.int
.public static Integer valueOf(String s) throws NumberFormatException
parseInt(java.lang.String)
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))
s
 the string to be parsed.Integer
initialized to the
value represented by the string argument.public byte byteValue()
public short shortValue()
public int intValue()
int
value represented by this object.public long longValue()
int
value represented by this object that is
converted to type long
and the result of the
conversion is returned.public float floatValue()
int
value represented by this object is
converted to type float
and the result of the
conversion is returned.public double doubleValue()
int
value represented by this object is
converted to type double
and the result of the
conversion is returned.public String toString()
toString(int)
method.public int hashCode()
public boolean equals(Object obj)
true
if and only if the argument is not
null
and is an Integer
object that contains
the same int
value as this object.obj
 the object to compare with.true
if the objects are the same;
false
otherwise.public static Integer getInteger(String nm)
The first argument is treated as the name of a system property.
System properties are accessible through the
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, 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)
nm
 property name.Integer
value of the property.System.getProperty(java.lang.String)
,
System.getProperty(java.lang.String, java.lang.String)
public static Integer getInteger(String nm, int val)
The first argument is treated as the name of a system property.
System properties are accessible through getProperty
,
a method defined by the System
class. 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, or if the
property does not have the correct numeric format, then an
Integer
object that represents the value of the
second argument is returned.
In other words, this method returns an Integer
object
equal to the value of:
but in practice it may be implemented in a manner such as: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.nm
 property name.val
 default value.Integer
value of the property.System.getProperty(java.lang.String)
,
System.getProperty(java.lang.String, java.lang.String)
public static Integer getInteger(String nm, Integer val)
getProperty
,
a method defined by the System
class. The string value of
this property is then interpreted as an integer value, as per the
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 for the method
valueOf(java.lang.String, int)
with radix 16.
0
followed by another character, it is parsed as an
octal integer exactly as for the method
with radix 8.
The second argument is the default value. If there is no property of the specified name, or if the property does not have the correct numeric format, then the second argument is returned.
nm
 property name.val
 default value.Integer
value of the property.System.getProperty(java.lang.String)
,
System.getProperty(java.lang.String, java.lang.String)
,
decode(java.lang.String)
public static Integer decode(String nm) throws NumberFormatException
String
into an Integer
. Accepts
decimal, hexadecimal, and octal numbers, in the following formats:
[]The constant following an (optional) negative sign and/or "radix specifier" is parsed as by the[] 0x [] # [] 0
Integer.parseInt
method
with the specified radix (10, 8 or 16). This constant must be positive
or a NumberFormatException will result. The result is made negative if
first character of the specified String
is the negative
sign. No whitespace characters are permitted in the
String
.nm
 the String
to decode.Integer
represented by the specified string.String
does not
contain a parsable integer.parseInt(String, int)
public int compareTo(Integer anotherInteger)
anotherInteger
 the Integer
to be compared.0
if the argument Integer is equal to
this Integer; a value less than 0
if this Integer
is numerically less than the Integer argument; and a
value greater than 0
if this Integer is
numerically greater than the Integer argument
(signed comparison).public int compareTo(Object o)
compareTo(Integer)
. Otherwise,
it throws a ClassCastException
(as Integers are comparable
only to other Integers).o
 the Object
to be compared.0
if the argument is a Integer
numerically equal to this Integer; a value less than
0
if the argument is a Integer numerically
greater than this Integer; and a value greater than
0
if the argument is a Integer numerically
less than this Integer.ClassCastException
 if the argument is not an
Integer
.Comparable

Java Platform 1.2 

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