this is my first post.

I’m trying to write a palindrome checker using recursive (w3resource exercise) . The function pulls up first and last indexes of an array-transformed string if they match and reruns itself.

//checking if array is palindrome
  function isPal(arr){
    
    //array contains one or no char: this is palindrome
    if(arr.length <= 1) return true;
    
    //if first and last chars are the same
    if(arr[0] == arr[arr.length - 1]){
      //new array without these
      let newArr = arr.slice(1, arr.length -1);
      //rerun isPal with shortened arr
      isPal(newArr)
    }else{
      return false;
    }
  }
  isPal(strArray);
}
console.log(palindromeRec("A man, a plan, a canal - Panama"))

All works until array contains one or zero item, when function returns undefined instead of TRUE (base case).
Could someone help?