Check String Palindrome

Introduction

In this lab, you will learn how to write a C++ program that checks whether a given string is a palindrome or not. A palindrome is a string that is the same as its reverse. To check for a palindrome, we will reverse the given string and compare it with the original. If both the strings are the same, the given string is a palindrome, else, it is not.

Include Required Libraries and Define the main() Function

First, we will include the required libraries and define the main() function.

#include <iostream>
#include <string.h>

using namespace std;

int main() {
  // code goes here
  return 0;
}

Get Input String from the User

Next, we will get the input string from the user and store it in an array of characters.

char inputStr[100];
cout << "Enter a string: ";
cin >> inputStr;

Get the Length of the Input String

We will calculate the length of the input string using the strlen() function.

int strLength = strlen(inputStr);

Create an Array for Reverse String

Next, we will create an array for the reverse string.

char reverseStr[strLength];

Reverse the Input String

We will now reverse the input string and store it in the newly created array for the reverse string.

for(int i = 0; i < strLength; i++) {
    reverseStr[i] = inputStr[strLength - 1 - i];
}

Compare Original and Reverse Strings

Finally, we will compare the original and reverse strings to check whether the input string is a palindrome or not.

if(strcmp(inputStr, reverseStr) == 0) {
    cout << inputStr << " is a palindrome." << endl;
} else {
    cout << inputStr << " is not a palindrome." << endl;
}

Full Code

#include <iostream>
#include <string.h>

using namespace std;

int main() {
    char inputStr[100];
    cout << "Enter a string: ";
    cin >> inputStr;

    int strLength = strlen(inputStr);
    char reverseStr[strLength];

    for(int i = 0; i < strLength; i++) {
        reverseStr[i] = inputStr[strLength - 1 - i];
    }

    if(strcmp(inputStr, reverseStr) == 0) {
        cout << inputStr << " is a palindrome." << endl;
    } else {
        cout << inputStr << " is not a palindrome." << endl;
    }

    return 0;
}

Summary

In this lab, you learned how to write a C++ program that checks whether a given string is a palindrome or not. You can now use this program to quickly check if any string is a palindrome or not.