Write a program to check a number is palindrome or not?

What is palindrome?

A palindrome is a sequence of numbers or letters that match if we read from left to right and from right to left.

When we reverse a number or a string, if the reserved number or string is equal to the original number or string, it is called a palindrome.

Examples of palindrome number or string:

Examples of palindrome number or string: 12321, madam, etc.

Example of palindrome function:

Write an isPalindrome function without converting the integer to a string.

function isPalindrome(num) {
    if (num < 0) return false;

    let result = 0;
    let originalNum = num;

    while (1) {
        const rem = num % 10;
        num = parseInt(num / 10);

        result = result * 10 + rem;
        if (num < 1) break;
    }

    return originalNum === result;
}

console.log(isPalindrome(1004006004001));

Palindrome algorithm steps with string:

• Get a string or number from the user.
• Take a temporary variable that contains numbers.
• Reverse the given number.
• Compare the original number and reversed number.
• If the temporary and the original number are the same, then the number or string is a palindrome.
• Otherwise, the given string or number is not a palindrome.

Example:

    function checkPalindrome(str) {
        // convert string to an array
        const array = string.split('');
        // reverse the array values
        const reverseValues = array.reverse();
        // convert array to string
        const reverseString = reverseValues.join('');

        if(string === reverseString) {
            console.log('This is a palindrome');
        }
        else {
            console.log('This is not a palindrome');
        }
    }
    
    //take input
    const string = prompt('Enter a string: ');
    checkPalindrome(string);

Palindrome algorithm with string:

 const isPalindrome = (s) => {
     let i = 0;
     let j = s.length - 1;

     while (i < j) {
         if (s[i] === s[j]) {
             i++;
             j--;
         } else {
             return false;
         }
     }
     return true;
 }

 console.log(isPalindrome('aaba')); // true