JSFiddle - React, Tailwind, and code Playground

by f0t0n

HTML

<textarea id="res"></textarea>

CSS

textarea {
    width: 400px;
    height: 300px;
    resinze: none;
}

JavaScript

var console$ = $('#res');

function printLn(s) {
    print(Array.prototype.join.call(arguments, ''), "\n");
}

function print(s) {
    console$[0].value += Array.prototype.join.call(arguments, '');
    console$.scrollTop(console$[0].scrollHeight - console$.height());
}

var re = /^https?:\/\/.+?\?.*?PostID=(\d+)/;

function getPostId(url) {
    var matches = re.exec(url);
    return matches ? matches[1] : null;
}

var correctInputStr = 'http://www.roblox.com/Forum/ShowPost.aspx?PostID=78212279',
    incorrectInputStr = 'http://www.roblox.com/Forum/ShowPost.aspx?PostID=x78212279';

printLn(getPostId(correctInputStr));
printLn(getPostId(incorrectInputStr));