Java Program to illustrate the Usage of HexaDecimal

A decimal number is the sum of digits multiplied with a power of 10. Decimal numbers are represented with base 10 whereas hexadecimal Number is the sum of digits multiplied with the power of 16, somehow there are similar traits in the internal working of them just they are two different ways to present a number. The hexadecimal system has 16 different digit symbols. Different numbers can be generated using the combination of digits from 0 to 15. The representation in the hexadecimal system is the same as the decimal number system from 0 to 9 but then onwards it changes.

Representation:

 Decimal Number    Hexadecimal Number Equivalent

        0      —>      0

         :   :

        9      —>      9

       10      —>      A

       11      —>      B

       12      —>      C

       13      —>      D

       14      —>      E

       15      —>      F

Illustration: Internal Working

A. Decimal to Hexadecimal Number System

(1) (13)10 --> (D)16
    Directly can be written 13 as D in hexadecimal system
     
(2) (16)10 ---> (10)16
    ( 16 )16 = ( 1 x 161) + ( 0 * 160)
  
(3) (59)10 ---> (3B)16
   ( 59 )10 --> ( 3 * 161) + (11 * 160)

Conclusion:

For a Decimal Number system-> ( 421 )10 = (4 x 102) + (2 x 101) + (1 x 100)

B. Similarly ,Hexadecimal to Decimal Number System
   (8A)16 ---> (138)10
    (8A)16 --> (8 x 161) + (10 x 160)

Conclusion:

In Java programs, hexadecimal numbers are written by placing 0x before numbers.

Below are 4 examples been discusses to illustrate the usage of Hexadecimal Number

1. Converting Hex number to Decimal number
2. Converting Decimal number to Hex number
3. Converting Hex number to Long number
4. Converting Long number to Hex number

Example 1: Java program to convert Hex number to Decimal number

Java

// Java program to convert Hex number to Decimal number

// Importing input/output java library
import java.io.*;

class GFG {

    // Main driver method
    public static void main(String[] args)
    {

        // Hexadecimal number stored in a string
        String hexNum = "100";

        /* Random hexadecimal number */

        // Passing hexnum and base as parameters
        // which is 16 to parseInt function
        int decimal = Integer.parseInt(hexNum, 16);

        // Printing the output result as
        // decimal equivalent of hexa-decimal
        System.out.println("Decimal value is " + decimal);
    }
}

Output

Decimal value is 256

 Example 2: Java program to convert Decimal number to Hex number

Java

// Java Program to Illustrate the Usage of HexaDecimal

// Importing input/output java library
import java.io.*;

class GFG {

    // Main driver function
    public static void main(String[] args)
    {

        /* Decimal number to be converted */
        int i = 257;

        // Using toHexString() method for getting decNum and
        // Storing the hexaDecNum in a string
        String hex = Integer.toHexString(i);

        // Printing hexaDecNum of decNum
        System.out.println("Hex value is " + hex);
    }
}

Output

Hex value is 101

Example 3: Java program to convert Hex number to Long number

Java

// Java Program to Illustrate the Usage of HexaDecimal

// Importing input/output java library
import java.io.*;

class GFG {

    // Main driver method
    public static void main(String[] args)
    {

        // Hexadecimal number stored in a string
        String hexNum = "10000";

        // passing hexnum and base as parameters
        // which is 16 to parseLong function
        long num = Long.parseLong(hexNum, 16);

        // Printing long value of HexaDecNum
        System.out.println("Long value is " + num);
    }
}

Output

Long value is 65536

Example 4: Java program to convert Long number to Hex number 

Java

// Java Program to Illustrate the Usage of HexaDecimal

// Importing java input/output library
import java.io.*;

class GFG {

    // Main driver function
    public static void main(String[] args)
    {

        /* Long number to be converted */
        long i = 1024;

        // Storing the result in a string
        String hex = Long.toHexString(i);

        // Displaying Result
        System.out.println("Hex value is " + hex);
    }
}

Output

Hex value is 400

Note: There are two more conventions for hexadecimal numbers, 400h or $400. They both are the same as 0x400.