How to solve leetcode problem in JavaScript to check if an integer is a palindrome

Question

Here is the code which i tried to solve, for the leetcode problem in javaScript https://leetcode.com/problems/palindrome-number/ Problem i am facing:

It is working for even number of digits in an intArr, but not for odd.

let myFunc = (num) => Number(num);
var intArr = Array.from(String(myInt), myFunc);
console.log(intArr.length);
const half = Math.ceil(intArr.length / 2);
const firstHalf = intArr.splice(0, half);
const secondHalf = intArr.splice(-half).reverse();
if (intArr.length % 2 != 0) {
  firstHalf.pop();
}
console.log(firstHalf);
console.log(secondHalf);
arrayEquals(firstHalf, secondHalf);
function arrayEquals(firstHalf, secondHalf) {
  if (
    Array.isArray(firstHalf) &&
    Array.isArray(secondHalf) &&
    firstHalf.length === secondHalf.length &&
    firstHalf.every((val, index) => val === secondHalf[index])
  ) {
    console.log("true");
  } else {
    console.log("false");
  }
}
}
isPalindrome(1221);
isPalindrome(12321);

Please let me know how can i solve this problem. Please correct me if I was wrong in implementing this solution, Thank you.

`splice` updates `intArr`, when you check `intArr.length % 2`, it doesn't return the value you expected — ProDec, Dec 17 '21 at 05:48
Where is the function defined? How about this? `const isPalindrome = num => num.toString().split('').map(v => +v).every((v,i,a) => v === a.reverse()[i]);` — PeterKA, Dec 17 '21 at 06:20
Does this answer your question? [How do I check if a number is a palindrome?](https://stackoverflow.com/questions/199184/how-do-i-check-if-a-number-is-a-palindrome) — A1exandr Belan, Dec 18 '21 at 07:51

score 0 · Answer 1 · answered Apr 26 '22 at 19:08

You can check weather a number or string is a Palindrome or not by using following Function

const isPalindrome = (input) => {

const arr = (input.toString()).split('');
  let isPalindromeInput = true, inputLengthMid = Math.floor(arr.length / 2);
  for(let i=0, j=arr.length - 1; i <= inputLengthMid && j >= inputLengthMid; i++, j--) {
    if(arr[i].toLowerCase() !== arr[j].toLowerCase()){
      isPalindromeInput = false;
      break;
    }
  }
  return isPalindromeInput;
}

console.log('isPalindrome : ', isPalindrome('Neveroddoreven'));
console.log('isPalindrome : ', isPalindrome(12321));
console.log('isPalindrome : ', isPalindrome(1221));
console.log('isPalindrome : ', isPalindrome(11214211));

How to solve leetcode problem in JavaScript to check if an integer is a palindrome

1 Answers1