Java Integer - decode() Method

The java.lang.Integer.decode() method is used to decode a String into an Integer. Accepts decimal, hexadecimal, and octal numbers given by the following grammar:

DecodableString:

• Sign_opt DecimalNumeral
• Sign_opt 0x HexDigits
• Sign_opt 0X HexDigits
• Sign_opt # HexDigits
• Sign_opt 0 OctalDigits

Sign:

• +
• -

The sequence of characters following an optional sign and/or radix specifier ("0x", "0X", "#", or leading zero) is parsed as by the Integer.parseInt method with the indicated radix (10, 16, or 8). This sequence of characters must represent a positive value or a NumberFormatException will be thrown. The result is negated if first character of the specified String is the minus sign. No whitespace characters are permitted in the String.

Syntax

public static Integer decode(String nm)
                      throws NumberFormatException

Parameters

Return Value

Returns an Integer object holding the int value represented by nm.

Exception

Throws NumberFormatException, if the String does not contain a parsable integer.

Example:

In the example below, the java.lang.Integer.decode() method is used to decode a String into an Integer.

import java.lang.*;

public class MyClass {
  public static void main(String[] args) {
    
    //creating a string holding int value
    String x1 = "25";    //decimal number
    String x2 = "0x6f";  //hexadecimal number
    String x3 = "0X6B";  //hexadecimal number
    String x4 = "-#6c";  //hexadecimal number
    String x5 = "027";   //octal number

    //creating Integer object
    Integer y1 = Integer.decode(x1);
    Integer y2 = Integer.decode(x2);
    Integer y3 = Integer.decode(x3);
    Integer y4 = Integer.decode(x4);
    Integer y5 = Integer.decode(x5);

    //printing the Integer object 
    System.out.println("The Integer object y1 is: " + y1);
    System.out.println("The Integer object y2 is: " + y2);  
    System.out.println("The Integer object y3 is: " + y3);  
    System.out.println("The Integer object y4 is: " + y4);  
    System.out.println("The Integer object y5 is: " + y5);     
  }
}

The output of the above code will be:

The Integer object y1 is: 25
The Integer object y2 is: 111
The Integer object y3 is: 107
The Integer object y4 is: -108
The Integer object y5 is: 23