JSFiddle - React, Tailwind, and code Playground

by tonyleeper

HTML

<div id="console"></div>

CSS

#console {
    height: 400px;
    background-color: black;
    color: white;
}

JavaScript

/**
    {string}.startsWith() extension method
*/

var log = function (value) {
    document.getElementById("console").innerHTML += value + "<br />";
};

if (typeof String.prototype.startsWith !== 'function') {
    String.prototype.startsWith = function (value) {
        if (value.length > this.length) {
            return false;
        }

        for (var i = 0; i < value.length; i++) {
            if (this.charAt(i) !== value.charAt(i)) {
                return false;
            }
        }

        return true;
    };
}

var message = new String("Hello world!");
log(message);
log(message.startsWith("Goodbye"));
log(message.startsWith("Hello"));