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| Chapter 25 The java.lang Package |

## 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()

java.lang.InstantiationException (JDK 1.0) |  | java.lang.InternalError (JDK 1.0)