JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <p>hello</p>

JavaScript

var str = "Rahul";
var str_array = str.split("");
var result_array = [];
var result_str = "";

for (var i = str_array.length - 1, j = 0; i >= 0, j <= str_array.length - 1; i--, j++) {
    result_array[j] = str_array[i];
}

result_array.forEach(function (element) {
    result_str = result_str + element;
});

alert(result_str);