Java Integer decode() method

The decode() method of Integer class decodes a String into an Integer. It can accept decimal, hexadecimal and octal numbers.

Syntax

public static Integer decode(String nm) throws NumberFormatException

Parameters

The parameter ‘nm’ represents the String to decode.

Throws:

The decode() method throws :

NumberFormatException- if the String does not contains a parsable integer.

Return Value

This method returns an Integer object holding the int value of string ‘nm’.

Example 1

public class JavaIntegerDecodeExample1 {
    public static void main(String[] args) {
        String str="12";
        //decodes a String into a Integer
        Integer val=Integer.decode(str);
        System.out.println(val);
    }
}

Output

12

Example 2

public class JavaIntegerDecodeExample2 {
    public static void main(String[] args) {
        //for Min.VALUE value it will give an NumberFormatException
        String str="Integer.MIN_VALUE";
        Integer b1=Integer.decode(str);
        System.out.println(b1);
    }
}

Output

Exception in thread "main" java.lang.NumberFormatException: For input string: "Integer.MIN_VALUE"
            at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
            at java.lang.Integer.parseInt(Integer.java:580)
            at java.lang.Integer.valueOf(Integer.java:740)
            at java.lang.Integer.decode(Integer.java:1197)
            at com.TutorialAndExample.JavaIntegerDecodeExample2.main(JavaIntegerDecodeExample2.java:7)

Example 3

public class JavaIntegerDecodeExample3 {
    public static void main(String[] args) {
        //for Min.VALUE value it will give an NumberFormatException
        String str="null";
        Integer b1=Integer.decode(str);
        System.out.println(b1);
    }
}

Output

Exception in thread "main" java.lang.NumberFormatException: For input string: "null"
            at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
            at java.lang.Integer.parseInt(Integer.java:580)
            at java.lang.Integer.valueOf(Integer.java:740)
            at java.lang.Integer.decode(Integer.java:1197)
            at com.TutorialAndExample.JavaIntegerDecodeExample3.main(JavaIntegerDecodeExample3.java:8)