Java Program to convert number from decimal to hexa-decimal and vice-versa.
Objective
Write a Java program to convert a Decimal number to Hexadecimal and vice-versa.
Algorithm / Approach
- To convert Dec to Hex: Read a decimal string, parse it to an
int, and useString.format("%X", deci)to output the Hex equivalent. - To convert Hex to Dec: Read a Hex string, and use
Integer.valueOf(hex, 16)to parse it back into a base-10 integer.
Test.java
import java.util.*;
class Test {
public static void main(String [] ar){
Scanner sc = new Scanner(System.in);
System.out.print("Value in Dec:");
String dec = sc.nextLine();
int deci = Integer.parseInt(dec);
String dectohex;
dectohex = String.format("%X",deci);
System.out.println("Hex : "+dectohex);
System.out.println("---------");
System.out.print("Value in Hex:");
String hex = sc.nextLine();
int hextodec = Integer.valueOf(hex,16);
System.out.println("Dec : "+hextodec);
}
}Expected Output
Value in Dec:106 Hex : 6A ------------- Value in Hex:6B Dec : 107
Explanation of the Program
- Hexadecimal is a base-16 number system (using 0-9 and A-F).
- Java's
Integerwrapper class provides built-in methods to parse strings of different mathematical bases (radix). By passing 16 as the second argument tovalueOf, we tell Java to interpret the letters as math values.
Complexity
Time Complexity
O(1)
Space Complexity
O(1)
