Checking if a string can be made palindrome in JavaScript

We are required to write a JavaScript function that takes in a string as the first and the only argument.

The task of our function is to check whether we can make that string a palindrome string by deleting at most one character from the string. If we can do so, the function should return true, false otherwise.

For example −

If the input string is −

const str = 'kjlk';

Then the output should be −

const output = true;

because by deleting 'l' from the string, only 'kjk' will be left which is a palindrome string.

Example

The code for this will be −

const str = 'kjlk';
const isPalindrome = (str = '', start, end) => {
   while (start < end) {
      if (str[start] != str[end]) {
         return false;
      };
      start ++;
      end --;
   };
   return true;
};
const canMakePalindrome = (str = '') => {
   let left = 0, right = str.length - 1;
   while (left < right - 1) {
      if (str[left] !== str[right]) {
         if (isPalindrome(str, left, right - 1)) {
            return true;
         };
         if (isPalindrome(str, left + 1, right)) {
            return true;
         };
         return false;
      }else {
         left ++;
         right --;
      };
   };
   return true;
}
console.log(canMakePalindrome(str));

Output

And the output in the console will be −

true