title: Why is my Palindrome code running true for every scenario?
body: <p>This code returns true for every scenario; it returns true if it's a palindrome and it returns true if it's not a palindrome.</p>
  <pre><code> function isPalindrome(string){
    string = string.toLowerCase();
    var charactersArr = string.split(' ');
    var validCharacters = 'abcdefghijklmnopqrstuvwxyz'.split(' ');
  
    var lettersArr = [];
    charactersArr.forEach(char =&gt; {
      if (validCharacters.indexOf(char)&gt; - 1) lettersArr.push(char);
    });
    return lettersArr.join(' ') === lettersArr.reverse().join(' ');
  }
  isPalindrome(&quot;Taco Cat&quot;);
  </code></pre>