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§1.8 Class Integer
public final class java.lang.Integer
extends java.lang.Number (I-§1.11)
{
// Fields
public final static int MAX_VALUE; §1.8.1
public final static int MIN_VALUE; §1.8.2
// Constructors
public Integer(int value); §1.8.3
public Integer(String s); §1.8.4
// Methods
public double doubleValue(); §1.8.5
public boolean equals(Object obj); §1.8.6
public float floatValue(); §1.8.7
public static Integer getInteger(String nm); §1.8.8
public static Integer getInteger(String nm, int val); §1.8.9
public static Integer getInteger(String nm, Integer val); §1.8.10
public int hashCode(); §1.8.11
public int intValue(); §1.8.12
public long longValue(); §1.8.13
public static int parseInt(String s); §1.8.14
public static int parseInt(String s, int radix); §1.8.15
public static String toBinaryString(int i); §1.8.16
public static String toHexString(int i); §1.8.17
public static String toOctalString(int i); §1.8.18
public String toString(); §1.8.19
public static String toString(int i); §1.8.20
public static String toString(int i, int radix); §1.8.21
public static Integer valueOf(String s); §1.8.22
public static Integer valueOf(String s, int radix); §1.8.23
}
This 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 a number of 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.
MAX_VALUE
public final static int MAX_VALUE = 2147483647
- The largest value of type int.
MIN_VALUE
public final static int MIN_VALUE = -2147483648
- The smallest value of type int.
Integer
public Integer(int value)
- Constructs a newly allocated Integer object that represents the primitive int argument.
- Parameters:
value
-
the value to be reprsented by the Integer
Integer
public Integer(String s)
throws NumberFormatException
- Constructs a newly allocated Integer object that represents the value represented by the string The string is converted to an int value as if by the valueOf method (I-§1.8.22).
- Parameters:
s
-
the String to be converted to an Integer
- Throws
- NumberFormatException (I-§1.41)
- If the String does not contain a parsable integer.
doubleValue
public double doubleValue()
- Returns:
- The int value represented by this object is converted to type double and
the result of the conversion is returned.
- Overrides:
- doubleValue in class Number (I-§1.11.1).
equals
public boolean equals(Object obj)
- 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.
- Parameters:
obj
-
the object to compare with
- Returns:
- true if the objects are the same; false otherwise.
- Overrides:
- equals in class Object (I-§1.12.3).
floatValue
public float floatValue()
- Returns:
- the int value represented by this object is converted to type float and the
result of the conversion is returned..
- Overrides:
- floatValue in class Number (I-§1.11.2).
getInteger
public static Integer getInteger(String nm)
- Determines the integer value of the system property with the specified
name.
- The first argument is treated as the name of a system property to be
obtained as if by the method System.getProperty (I-§1.18.10). The string value
of this property is then interpreted as an integer value and an Integer object
representing this value is returned. The full details of the possible numeric
formats are given in I-§1.8.10.
- If there is no property with the specified name, or if the property does not
have the correct numeric format, then null is returned.
- Parameters:
nm
-
property name
- Returns:
- the Integer value of the property.
getInteger
public static Integer getInteger(String nm, int val)
- Determines the integer value of the system property with the specified
name.
- The first argument is treated as the name of a system property to be
obtained as if by the method System.getProperty (I-§1.18.10). The string value
of this property is then interpreted as an integer value and an Integer object
representing this value is returned. The full details of the possible numeric
formats are given in I-§1.8.10.
- 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.
- Parameters:
nm
-
property name
val
-
default value
- Returns:
- the Integer value of the property.
getInteger
public static Integer getInteger(String nm, Integer val)
- Determines the integer value of the system property with the specified
name.
- The first argument is treated as the name of a system property to be
obtained as if by the method System.getProperty (I-§1.18.10). The string value
of this property is then interpreted as an integer value and an Integer object
representing this value is returned.
- If the property value begins with "0x" or "#", not followed by a minus sign,
the rest of it is parsed as a hexadecimal integer exactly as for the method
Integer.valueOf (I-§1.8.23) with radix 16.
- If the property value begins with "0" then it is parsed as an octal integer
exactly as for the method Integer.valueOf (I-§1.8.23) with radix 8.
- Otherwise the property value is parsed as a decimal integer exactly as for
the method Integer.valueOf (I-§1.8.23) with radix 10.
- 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.
- Parameters:
nm
-
property name
val
-
default value
- Returns:
- the Integer value of the property.
hashCode
public int hashCode()
- Returns:
- a hash code value for this object.
- Overrides:
- hashCode in class Object (I-§1.12.6).
intValue
public int intValue()
- Returns:
- The int value represented by this object is returned.
- Overrides:
- intValue in class Number (I-§1.11.3).
longValue
public long longValue()
- Returns:
- The int value represented by this object is converted to type long and
the result of the conversion is returned..
- Overrides:
- longValue in class Number (I-§1.11.4).
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 '-' to indicate a negative value.
- Parameters:
s
-
a string
- Returns:
- the integer represented by the argument in decimal.
- Throws
- NumberFormatException (I-§1.41)
- If the string does not contain a parsable integer.
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 Character.digit (I-§1.2.7) returns a
nonnegative value), except that the first character may be the an ASCII
minus sign '-' to indicate a negative value. The resulting integer value is
returned.
- Parameters:
s
-
the String containing the integer
radix
-
the radix to be used
- Returns:
- the integer represented by the string argument in the specified radix.
- Throws
- NumberFormatException (I-§1.41)
- If the string does not contain a parsable integer.
toBinaryString1
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 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.
- Parameters:
i
-
an integer
- Returns:
- the string representation of the unsigned integer value represented by
the argument in binary (base 2).
toHexString2
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 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.
- Parameters:
i
-
an integer
- Returns:
- the string representation of the unsigned integer value represented by
the argument in hexadecimal (base 16).
toOctalString3
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 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.
- Parameters:
i
-
an integer
- Returns:
- the string representation of the unsigned integer value represented by
the argument in octal (base 8).
toString
public String toString()
- Returns:
- a string representation of the value of this object in base 10.
- Overrides:
- toString in class Object (I-§1.12.9).
toString
public static String toString(int i)
- Parameters:
i
-
an integer to be converted
- Returns:
- a string representation of the argument in base 10.
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 (I-§1.2.3) or larger than Character.MAX_RADIX (I-§1.2.1), then the radix 10 is used instead.
- If the first argument is negative, the first element of the result is the ASCII
minus characer '-' . If the first argument is not negative, no sign character
appears in the result. The following ASCII characters are used as digits:
- 0123456789abcdefghijklmnopqrstuvwxyz
- Parameters:
i
-
an integer
radix
-
the radix
- Returns:
- a string representation of the argument in the specified radix.
valueOf
public static Integer valueOf(String s)
throws NumberFormatException
- Parameters:
s
-
the string to be parsed
- Returns:
- a newly constructed Integer initialized to the value represented by the
string argument.
- Throws
- NumberFormatException (I-§1.41)
- If the string does not contain a parsable integer.
valueOf
public static Integer valueOf(String s, int radix)
throws NumberFormatException
- Parameters:
s
-
the string to be parsed
- Returns:
- a newly constructed Integer initialized to the value represented by the
string argument in the specified radix.
- Throws
- NumberFormatException (I-§1.41)
- If the String does not contain a parsable integer.
1
This method is new in Java 1.1
2
This method is new in Java 1.1.
3
This method is new in Java 1.1.
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Java API Document (HTML generated by dkramer on April 22, 1996)
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