function reverseStr(str){
// console.log(str.length)
var rev = "";
for(var i = str.length -1; i >= 0; i--){
// console.log("str.substring(i):", str[i]);
rev += str[i];
}
return rev;
}
function reverse(str){
if(!str || typeof str != 'string' || str.length < 2 ) return str;
const backwards = [];
const totalItems = str.length - 1;
for(let i = totalItems; i >= 0; i--){
backwards.push(str[i]);
}
return backwards.join('');
}
function reverse2(str){
//check for valid input
return str.split('').reverse().join('');
}
const reverse3 = str => [...str].reverse().join('');
var text = reverseStr("my name is khan")
console.log(text)
