Check for Palindromes, i was trying this intermediate solution, but in for loop it is ( i < len-i ) works instead of ( i > len-i )which i think it should be a stop condition, right? can anyone figure out why?

Tell us what’s happening:

Your code so far

function palindrome(str) {
  // Good luck!
str = str.toLowerCase().replace(/[\W_]/g, '');
  for(var i = 0, len = str.length - 1; i < len-i; i++) {
    if(str[i] !== str[len-i]) {
      return false;
  return true;

palindrome("not a palindrome");

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Link to the challenge:

Actually, your (i < len - i) works, but all you really needed was (i < len).

If you use (i > len - i), then nothing inside the for loop would run, because when i is initialized to 0 and len is assigned str.length -1, the for loop condition would be evaluating 0 < len - 0, so no matter what the value of len is (0, 1, 2, 3, 4, 5…100), the for loop condition would evaluate to false, so the for loop code block would never execute.

yea, i figure out eventually, i took the wrong note when i study for loop, and it mistake me all the time. i thought it is a stop condition when it is true, which actually it is a stop condition when it is false. a false note really let me ask stupid question…lol