Java Convert Hexadecimal to Decimal

Let's see the simple example of converting hexadecimal to decimal in java.

public class HexToDecimalExample1{  
public static void main(String args[]){  
String hex="a";  
int decimal=Integer.parseInt(hex,16);  
System.out.println(decimal);  
}}  

Output:

10

Let's see another example of Integer.parseInt() method.

public class HexToDecimalExample2{  
public static void main(String args[]){  
System.out.println(Integer.parseInt("a",16));  
System.out.println(Integer.parseInt("f",16));  
System.out.println(Integer.parseInt("121",16));  
}}  

Output:

10
15
289

Java Hexadecimal to Decimal conversion: Custom Logic

We can convert hexadecimal to decimal in java using custom logic.

public class HexToDecimalExample3{    
public static int getDecimal(String hex){  
    String digits = "0123456789ABCDEF";  
             hex = hex.toUpperCase();  
             int val = 0;  
             for (int i = 0; i < hex.length(); i++)  
             {  
                 char c = hex.charAt(i);  
                 int d = digits.indexOf(c);  
                 val = 16*val + d;  
             }  
             return val;  
}  
public static void main(String args[]){    
System.out.println("Decimal of a is: "+getDecimal("a"));  
System.out.println("Decimal of f is: "+getDecimal("f"));  
System.out.println("Decimal of 121 is: "+getDecimal("121"));  
}}    

Output:

Decimal of a is: 10
Decimal of f is: 15
Decimal of 121 is: 289