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Java in a Nutshell

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The java.lang Package
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25.32 java.lang.Integer (JDK 1.0)

This class provides an immutable object wrapper around the int primitive data type. This class also contains useful minimum and maximum constants and useful conversion methods. parseInt() and valueOf() convert a string to an int or to an Integer, respectively. Each can take a radix argument to specify the base that the value is represented in. decode() also converts a String to an Integer. It assumes a hexadecimal number if the string begins with "0X" or "0x," or an octal number if the string begins with "0". Otherwise, a decimal number is assumed.

toString() converts in the other direction, and the static version takes a radix argument. toBinaryString(), toOctalString(), and toHexString() convert an int to a string using base 2, base 8, and base 16. These methods treat the integer as an unsigned value.

Other routines return the value of an Integer as various primitive types, and finally, the getInteger() methods return the integer value of a named property from the system property list or the specified default value.

public final class Integer extends Number {
    // Public Constructors
            public Integer(int value);
            public Integer(String s) throws NumberFormatException;
    // Constants
            public static final int MAX_VALUE;
            public static final int MIN_VALUE;
        1.1public static final Class TYPE;
    // Class Methods
        1.1public static Integer decode(String nm) throws NumberFormatException;
            public static Integer getInteger(String nm);
            public static Integer getInteger(String nm, int val);
            public static Integer getInteger(String nm, Integer val);
            public static int parseInt(String s, int radix) throws NumberFormatException;
            public static int parseInt(String s) throws NumberFormatException;
            public static String toBinaryString(int i);
            public static String toHexString(int i);
            public static String toOctalString(int i);
            public static String toString(int i, int radix);
            public static String toString(int i);
            public static Integer valueOf(String s, int radix) throws NumberFormatException;
            public static Integer valueOf(String s) throws NumberFormatException;
    // Public Instance Methods
        1.1public byte byteValue();  // Overrides Number
            public double doubleValue();  // Defines Number
            public boolean equals(Object obj);  // Overrides Object
            public float floatValue();  // Defines Number
            public int hashCode();  // Overrides Object
            public int intValue();  // Defines Number
            public long longValue();  // Defines Number
        1.1public short shortValue();  // Overrides Number
            public String toString();  // Overrides Object
}

Hierarchy:

Object->Number(Serializable)->Integer

Passed To:

Integer.getInteger()

Returned By:

Integer.decode(), Integer.getInteger(), Integer.valueOf()


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