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Java Exercises: Convert a decimal number to hexadecimal number

Java Basic: Exercise-20 with Solution

Write a Java program to convert a decimal number to hexadecimal number.

Decimal number: The decimal numeral system is the standard system for denoting integer and non-integer numbers. It is also called base-ten positional numeral system.

Hexadecimal number: Hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0-9 to represent values zero to nine, and A, B, C, D, E, F (or alternatively a, b, c, d, e, f) to represent values ten to fifteen.

Test Data:
Input a decimal number: 15

Pictorial Presentation: Decimal to Hexadecimal number

Java: Convert a decimal number to hexadecimal number

Sample Solution:

Java Code:

import java.util.Scanner;
public class Exercise20 {
      public static void main(String args[])
    {
        int dec_num, rem;
        String hexdec_num="";
        
        /* hexadecimal number digits */
        
        char hex[]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
        
        Scanner in = new Scanner(System.in);
		
        System.out.print("Input a decimal number: ");
        dec_num = in.nextInt();
		
        while(dec_num>0)
        {
            rem = dec_num%16;
            hexdec_num = hex[rem] + hexdec_num;
            dec_num = dec_num/16;
        }
        System.out.print("Hexadecimal number is : "+hexdec_num+"\n");         
    }
}

Sample Output:

Input a decimal number: 15                                                                                    
Hexadecimal number is : F 

Flowchart:

Flowchart: Java exercises: Convert a decimal number to hexadecimal number

Java Code Editor:

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Previous: Write a Java program to convert a decimal number to binary number.
Next: Write a Java program to convert a decimal number to octal number.

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Java: Tips of the Day

Try and catch:

Java is excellent at catching errors, but it can only recover gracefully if you tell it what to do. The cascading hierarchy of attempting to perform an action in Java starts with try, falls back to catch, and ends with finally. Should the try clause fail, then catch is invoked, and in the end, there's always finally to perform some sensible action regardless of the results. Here's an example:

try {
        cmd = parser.parse(opt, args); 
       
        if(cmd.hasOption("help")) {
                HelpFormatter helper = new HelpFormatter();
                helper.printHelp("Hello ", opt);
                System.exit(0);
                }
        else {
                if(cmd.hasOption("shell") || cmd.hasOption("s")) {
                String target = cmd.getOptionValue("tgt");
                } // else
        } // fi
} catch (ParseException err) {
        System.out.println(err);
        System.exit(1);
        } //catch
        finally {
                new Hello().helloWorld(opt);
        } //finally
} //try

It's a robust system that attempts to avoid irrecoverable errors or, at least, to provide you with the option to give useful feedback to the user. Use it often, and your users will thank you!

Ref: https://red.ht/3EZc9OC