Palindrome in Ruby without reverse code example

Example 1: palindrome recursion explained in ruby

function palindrome(str) {//\W removes all non-alphanumeric characters, 'g' flag stands for global search  var re = /[\W_]/g;   var strLow = str.toLowerCase().replace(re, '');  var reverseStr = strLow.split('').reverse().join('');    if (strLow === reverseStr) {    return true;  } else {    return false;  }}palindrome("eye");

Example 2: palindrome index explained in ruby

# Complete the palindromeIndex function below. def palindromeIndex(s)   # slen = s.length   splt = s.split('')    n = s.reverse   nsplt = n.split('')    if n == s     return -1   elsif n != s      splt.each do |p|                   if nsplt[p] != splt[p]         return p       end     end   else      return -1   end end