Javascript program to check Palindrome

Dec 22nd, 2022

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Introduction

In this article, we will learn how to write a function in JavaScript that determines whether a given string is a palindrome or not. A palindrome is a word, phrase, or sequence of characters that reads the same forwards and backwards.

Table of Contents:

  1. Introduction
  2. Understanding Palindromes
  3. Writing the Function in JavaScript
  4. Testing the Function
  5. Improving the Function
  6. Conclusion

Understanding Palindromes

To determine whether a string is a palindrome, we need to compare the string to its reverse. For example, the string “racecar” is a palindrome because it is spelled the same forwards and backwards. The string “hello” is not a palindrome because it is not spelled the same forwards and backwards.

Writing the Function in JavaScript

To write the function, we will follow these steps:

  • Create a function named isPalindrome that takes in a string as an argument.
  • Inside the function, we will use the split method to convert the string into an array of characters. We will then use the reverse method to reverse the order of the characters in the array.
  • Next, we will use the join method to convert the reversed array of characters back into a string.
  • Finally, we will compare the original string to the reversed string. If they are the same, the function will return true, indicating that the string is a palindrome. If they are not the same, the function will return false, indicating that the string is not a palindrome.

Here is what the function will look like:


function isPalindrome(str) {
  const reversed = str.split('').reverse().join('');
  return str === reversed;
}

Testing the Function

To test the function, we can call it with various strings as arguments and print the result to the console. Here is an example:


console.log(isPalindrome('racecar')); // true
console.log(isPalindrome('hello')); // false
console.log(isPalindrome('level')); // true
console.log(isPalindrome('rotator')); // true
console.log(isPalindrome('civic')); // true

Improving the Function

We can also make the function more robust by adding some additional checks. For example, we can make the function case-insensitive by converting the string to lowercase before comparing it to the reversed string. We can also remove any non-alphanumeric characters from the string before comparing it to the reversed string.

Here is an updated version of the function that includes these additional checks:


function isPalindrome(str) {
  str = str.toLowerCase().replace(/[^a-z0-9]/g, '');
  const reversed = str.split('').reverse().join('');
  return str === reversed;
}

With this function, we can now determine whether a given string is a palindrome or not with greater accuracy and flexibility.

Conclusion

In this article, we learned how to write a function in JavaScript that determines whether a given string is a palindrome or not. By following the steps outlined in this article, you can now easily check whether a string is a palindrome or not using JavaScript.

This article was generated by ChatGPT to demonstrate its capabilities.