How to convert Decimal number to Hexadecimal number in Java?

Problem Description :

Write a program in Java that converts Decimal number to Hexadecimal number.

Decimal to Hexadecimal conversion

Concept :

Click here to learn how to convert decimal number to hexadecimal number Mathematically. We are using Method 2 : Fast Method (Remainders).

Recommended :

Learn different methods of reversing a String, using.

• Library method of StringBuilder class.
• Iteration
• Recursion

Java Program :

	package com.javamultiplex.baseconversion;
	import java.util.Scanner;
	/**
	*
	* @author Rohit Agarwal
	* @category Base Conversion
	* @problem Convert Decimal to Hexadecimal
	*
	*/
	public class DecimalToHexadecimal {
	public static void main(String[] args) {
	Scanner input = null;
	try {
	input = new Scanner(System.in);
	System.out.println("Enter decimal number : ");
	String number = input.next();
	if (isDecimalNumber(number)) {
	String hexadecimal = getHexadecimalNumber(number);
	System.out.println("Hexadecimal number : " + hexadecimal);
	} else {
	System.out.println("Please enter valid decimal number.");
	}
	} finally {
	if (input != null) {
	input.close();
	}
	}
	}
	private static String getHexadecimalNumber(String number) {
	// Converting String to Integer.
	int decimal = Integer.parseInt(number);
	int remainder = 0;
	StringBuilder hexadecimal = new StringBuilder();
	String result;
	while (decimal != 0) {
	remainder = decimal % 16;
	if (remainder >= 10 && remainder <= 15) {
	char hexChar = getHexadecimalCharacter(remainder);
	// Convert char to String.
	result = String.valueOf(hexChar);
	} else {
	// Convert int to String.
	result = String.valueOf(remainder);
	}
	// Add string to StringBuilder.
	hexadecimal.append(String.valueOf(result));
	decimal = decimal / 16;
	}
	// Reverse String using library function of StringBuilder class.
	return hexadecimal.reverse().toString();
	}
	private static char getHexadecimalCharacter(int remainder) {
	char ch = '\u0000';
	switch (remainder) {
	case 10:
	ch = 'A';
	break;
	case 11:
	ch = 'B';
	break;
	case 12:
	ch = 'C';
	break;
	case 13:
	ch = 'D';
	break;
	case 14:
	ch = 'E';
	break;
	case 15:
	ch = 'F';
	break;
	}
	return ch;
	}
	private static boolean isDecimalNumber(String number) {
	// Regular expression that matches String containing only digits [0-9].
	String pattern = "^[0-9]+$";
	boolean result = false;
	if (number.matches(pattern)) {
	result = true;
	}
	return result;
	}
	}

view raw DecimalToHexadecimal.java hosted with ❤ by GitHub

Output :

Output - How to convert Decimal number to Hexadecimal number in Java?

References :

https://en.wikipedia.org/wiki/Regular_expression

http://docs.oracle.com/javase/7/docs/api/java/lang/String.html

https://docs.oracle.com/javase/7/docs/api/java/lang/StringBuilder.html

https://docs.oracle.com/javase/7/docs/api/java/lang/Integer.html

https://www.tutorialspoint.com/java/switch_statement_in_java.htm

Thank you friends, I hope you have clearly understood the solution of this problem. If you have any doubt, suggestion or query please feel free to comment below. You can also discuss this solution in our forum.

Tags :  Conversion problems, Decimal to Hexadecimal, Solution in Java, String, StringBuilder, Regular expressions, switch statement, if else statement, while loop.

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