JavaScript’s built-in constructors are difficult to subclass. This post explains why and presents solutions.

In the JavaScript world, one frequently encounters the words shim and polyfill. What are those things and what is the difference between them?

Duolingo achieves an impressive win-win: Customers get to learn a foreign language for free while helping the company translate texts.

Update 2012-01-29: The post “What is {} + {} in JavaScript?” looks at the addition operator in more detail.

This post describes how to do a limited version of operator overloading in JavaScript. With the technique described here, you’ll be able to implement a type StringBuilder that can be used as follows:

    var sb = new StringBuilder();
    sb << add("abc") << add("def");

And a type Point that can be used as follows:

    var p = new Point();
    p._ = new Point(1, 2) + new Point(3, 4) + new Point(5, 6);
    p._ = new Point(1, 2) * new Point(3, 4) * new Point(5, 6);

Update 2012-08-21: All posts about shell scripting via Node.js have the label “jsshell”.

Do you know JavaScript and want to write a shell script? Then you should give Node.js a try. It is easy to install and shell scripts are a great way to get to know it. This post explains the basics.

The following are the highlights of what is new in CSS 4 selectors:

Tweets marked with the hashtag #MovieLinesInCode express a movie line or title in programming language code. This post gives some examples in JavaScript; most of them are paraphrased from the blog post “Best of #MovieLinesInCode” by Arialdo Martini [link via Michael Haszprunar].

This post examines what options one has for handling footnotes and references in HTML. It then presents a library that helps you with handling them.

Update 2011-12-07: Added case 5 and a conclusion.

Short answer: never. This post looks at five possible exemptions from the rule to always use === and explains why they aren’t.

Update 2013-04-09: now simulates the approach of the ECMAScript 6 specification draft (search for "HomeObject" to find the relevant parts).

This post examines how super-references work in JavaScript and how they will be simplified by ECMAScript 6. To understand this post, it helps to be familiar with JavaScript inheritance. If you are not, consult [2].