Did you know that defining a property is not the same as assigning to it? This blog post explains the difference and its consequences. It has been triggered by an email from Allen Wirfs-Brock on the es-discuss mailing list.

TC39 (Technical Committee 39) works on the upcoming ECMAScript.next [1] standard. They have several meetings per year and in July, there was another one. This blog post summarizes the most important decisions. It is based on the following minutes by Rick Waldron:

• July 24, 2012
• July 25, 2012
• July 26, 2012

[Update 2015-02-15] Newer version of this blog post: “Classes in ECMAScript 6 (final semantics)”

During the July 2012 meeting of TC39 [1], classes have been accepted for ECMAScript 6, the upcoming version of the JavaScript language standard. This blog post explains how those classes work. It is based on Allen Wirfs-Brock’s annotated slides.

This blog post describes three tricks for working with arrays via apply.

When I tell non-programmers that what I do professionally involves JavaScript, I most commonly get the reaction: “Isn’t that that thing that you have to install and that makes the browser slow?”. This answer surprises me in two ways:

This blog post explores JavaScript’s eval function by implementing the foundation for an interactive command line. As a bonus, you’ll get to work with ECMAScript.next’s generators (which can already be tried out on current Firefox versions).

In the 1940s, the first computer programmers were all women. That only changed later. Quoting “Researcher reveals how ‘Computer Geeks’ replaced ‘Computer Girls’” by Brenda D. Frink for the Clayman Institute for Gender Research:

Update 2012-09-05: separated input and output.

Currently, you are forced to work with JavaScript code in either of two modes: You can either use a code editor and edit multiple lines or you can use an interactive command line and work with one line at a time (editing, evaluating). With jsrepl [GitHub project, live demo], I have prototyped a combination of both modes – no need to chose, any more.

In JavaScript, one has at most 53 bits for integers. This blog post explains how to work with large integers, by encoding them in strings.

James Burke’s npm module amdefine lets you write AMD modules [1] that also work on Node.js. To do so, you need to perform the following steps: