Week1 firstReverse

firstReverse-1

var userInput = prompt("Enter a String:");

function firstReverse(str) { 

  var result = '';
  for(var i=0; i<str.length; i++){
    result+=str.charAt(str.length-1-i);
  }
  return result;        
}

console.log(firstReverse(userInput));

firstReverse-10

function reverse(s) {
  if (s.length < 2)
    return s;
  var halfIndex = Math.ceil(s.length / 2);
  return reverse(s.substr(halfIndex)) +
         reverse(s.substr(0, halfIndex));
}

firstReverse-2

function reverse(s) {
  var o = '';
  for (var i = s.length - 1; i >= 0; i--)
    o += s[i];
  return o;
}

firstReverse-3

function reverse(s) {
  var o = [];
  for (var i = s.length - 1, j = 0; i >= 0; i--, j++)
    o[j] = s[i];
  return o.join('');
}

firstReverse-4

function reverse(s) {
  var o = [];
  for (var i = 0, len = s.length; i <= len; i++)
    o.push(s.charAt(len - i));
  return o.join('');
}

firstReverse-5

function reverse(s) {
  return s.split('').reverse().join('');
}

firstReverse-6

function reverse(s) {
  var i = s.length,
      o = '';
  while (i > 0) {
    o += s.substring(i - 1, i);
    i--;
  }
  return o;
}

firstReverse-7

function reverse(s) {
  return (s === '') ? '' : reverse(s.substr(1)) + s.charAt(0);
}

firstReverse-8

function reverse(s) {
  function rev(s, len, o) {
    return (len === 0) ? o : rev(s, --len, (o += s[len]));
  };
  return rev(s, s.length, '');
}

firstReverse-9

function reverse(s) {
  s = s.split('');
  var len = s.length,
      halfIndex = Math.floor(len / 2) - 1,
      tmp;
  for (var i = 0; i <= halfIndex; i++) {
    tmp = s[len - i - 1];
    s[len - i - 1] = s[i];
    s[i] = tmp;
  }
  return s.join('');
}