The only difference is brackets in the second loop. Its for checking if a given string is a palindrome.
function solution(str) {
var len = Math.floor(str.length / 2);
for (var i = 0; i < len; i++)
if (str[i] !== str[str.length -i -1])
return false;
return true;
/*var len = Math.floor(str.length / 2);
for (var i = 0; i < len; i++){
if (str[i] !== str[str.length - i - 1]) {
return false;
} else {
return true;
}
}*/
}