Program to Check if a String is Palindrome or Not

2025-11-04 python c c# js php palindrome beginner interview-question

This program checks whether a given string reads the same forward and backward. A string like madam, racecar, 121, or malayalam is considered a palindrome because its characters remain the same even after reversing.

Program Explanation

What is a Palindrome?

A palindrome is a string that remains unchanged when reversed.

Steps to Solve

  1. Take a string as input.
  2. Reverse the string using built-in functions or manual logic.
  3. Compare the original string with the reversed string.
  4. If both are equal → it is a palindrome.
  5. Otherwise → it is not a palindrome.

Key Points

  • Palindrome checking is usually case-sensitive unless handled separately.
  • Spaces and special characters can be ignored based on requirement.
  • This program checks the raw input directly.

Program Code


s = input("Enter a string: ")

rev = s[::-1]

if s == rev:
    print("Palindrome")
else:
    print("Not a palindrome")

            

#include <stdio.h>
#include <string.h>

int main() {
    char str[100], rev[100];

    printf("Enter a string: ");
    scanf("%s", str);

    strcpy(rev, str);
    strrev(rev);

    if (strcmp(str, rev) == 0)
        printf("Palindrome");
    else
        printf("Not a palindrome");

    return 0;
}


            

let s = prompt("Enter a string:");

let rev = s.split("").reverse().join("");

if (s === rev)
    console.log("Palindrome");
else
    console.log("Not a palindrome");

            

using System;

class Program {
    static void Main() {
        Console.Write("Enter a string: ");
        string s = Console.ReadLine();

        char[] arr = s.ToCharArray();
        Array.Reverse(arr);
        string rev = new string(arr);

        if (s == rev)
            Console.WriteLine("Palindrome");
        else
            Console.WriteLine("Not a palindrome");
    }
}

            

<?php
$s = readline("Enter a string: ");

$rev = strrev($s);

if ($s == $rev) {
    echo "Palindrome";
} else {
    echo "Not a palindrome";
}
?>
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