Java Long decode() method with Examples

Last Updated : 05 Dec, 2018

The java.lang.Long.decode() is a built in function in java that decodes a String into a Long. It accepts decimal, hexadecimal, and octal numbers.

Syntax:

public static Long decode(String number) throws NumberFormatException 

Parameter: 
number-  the number that has to be decoded into a Long.

Error and Exceptions:

NumberFormatException: If the String does not contain a parsable long, the program returns this error.

Returns: It returns the decoded string.

Program 1: The program below demonstrates the working of function.

// Java program to demonstrate 
// of java.lang.Long.decode() method 
import java.lang.Math; 
  
class GFG { 
  
    // driver code 
    public static void main(String args[]) 
    { 
  
        // demonstration of function 
        Long l = new Long(14); 
        String str = "54534"; 
  
        System.out.println("Number = "
                        + l.decode(str)); 
    } 
} 

Output:

Number = 54534

Program 2: The program demonstrates the conversions using decode() function

// Java program to demonstrate 
// of java.lang.Long.decode() method 
import java.lang.Math; 
  
class GFG { 
  
    // driver code 
    public static void main(String args[]) 
    { 
        // demonstration of conversions 
        String decimal = "10"; // Decimal 
        String hexa = "0XFF"; // Hexa 
        String octal = "067"; // Octal 
  
        // convert decimal val to number using decode() method 
        Integer number = Integer.decode(decimal); 
        System.out.println("Decimal [" + decimal + "] = " + number); 
  
        number = Integer.decode(hexa); 
        System.out.println("Hexa [" + hexa + "] = " + number); 
  
        number = Integer.decode(octal); 
        System.out.println("Octal [" + octal + "] = " + number); 
    } 
} 

Output:

Decimal [10] = 10
Hexa [0XFF] = 255
Octal [067] = 55

Program 3: The program demonstrates error and exceptions.

// Java program to demonstrate 
// of java.lang.Long.decode() method 
import java.lang.Math; 
  
class GFG { 
  
    // driver code 
    public static void main(String args[]) 
    { 
        // demonstration of errorand exception when 
        // a non-parsable Long is passed 
  
        String decimal = "1A"; 
  
        // throws an error 
        Integer number = Integer.decode(decimal); 
        System.out.println("string [" + decimal + "] = " + number); 
    } 
} 

Output:

 
Exception in thread "main" java.lang.NumberFormatException: For input string: "1A"
    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 GFG.main(File.java:16)