Two simple method achieve reversing the string

string_reversing.md

function reverseString(str) {
 //method 1.
  str = str.split('').reverse().join('');
  
  //method 2
  /*var str2 = "";
  for(var i = str.length-1;i>=0;i--){
    str2+=str.charAt(i);
   }
  str = str2;*/
  return str;
 }