Java Program to Reverse the given String using Stack

Given a String, write a java program to reverse the string using Stack

Java Code:


import java.util.Stack;


public class JavaExample {

    static void reverse(String input){
        StringBuffer output = new StringBuffer();
        if(input==null || input.isEmpty())
            return;

        Stack<Character> stack = new Stack<>();
        for (int i = 0; i <input.length() ; i++) {
            stack.add(input.charAt(i));
        }

        //traverse through stack, pop the characters and add it to StringBUffer
        while (stack.empty()==false){
            output.append(stack.pop());
        }

        System.out.println("Original String: " +  input);
        System.out.println("Reverse String: " + output);
    }

    public static void main(String[] args) {
        String input = "Code Examples";
        reverse(input);
    }
}

import java.util.Stack;

public class JavaExample {

static void reverse(String input){

StringBuffer output = new StringBuffer();

if(input==null || input.isEmpty())

return;

Stack<Character> stack = new Stack<>();

for (int i = 0; i <input.length() ; i++) {

stack.add(input.charAt(i));

}

//traverse through stack, pop the characters and add it to StringBUffer

while (stack.empty()==false){

output.append(stack.pop());

}

System.out.println("Original String: " + input);

System.out.println("Reverse String: " + output);

}

public static void main(String[] args) {

String input = "Code Examples";

reverse(input);

}

Output:


Original String: Code Examples
Reverse String: selpmaxE edoC

Original String: Code Examples

Reverse String: selpmaxE edoC

How to work

Initialize a StringBuffer, this will be our output.
Initialize a Stack.
Traverse through string, one character at a time and keep adding it to Stack.
While stack is not empty, keep popping out the characters from stack and add it to the output StringBuffer.
Print the output.

Java Program to Reverse the String entered by user using Stack

Java Code:


import java.util.Scanner;
import java.util.Stack;


public class JavaExample {

    static void reverse(String input){
        StringBuffer output = new StringBuffer();
        if(input==null || input.isEmpty())
            return;

        Stack<Character> stack = new Stack<>();
        for (int i = 0; i <input.length() ; i++) {
            stack.add(input.charAt(i));
        }

        //traverse through stack, pop the characters and add it to StringBUffer
        while (stack.empty()==false){
            output.append(stack.pop());
        }

        System.out.println("Original String: " +  input);
        System.out.println("Reverse String: " + output);
    }

    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        
        System.out.print("Enter a String:");
        String input = sc.nextLine();
        
        reverse(input);
    }
}

import java.util.Scanner;