Home - A Drip of JavaScript

We've talked in the past about different ways of iterating over arrays. But in this drip we'll take a look at one way not to do it.
JavaScript's for...in loop iterates over the enumerable properties of an object like so:
Because for...in operates on any JavaScript object, it is also possible to use it with arrays. For example:...

At one point or another almost every JavaScript developer has to deal with optimizing performance-critical code. But how exactly do you go about it? This drip will show you how to use console.time as a low-cost performance testing tool.
First, let's suppose that we have a scientific application that makes frequent use of the factorial function....

One of the most important things to understand about JavaScript is how to deal with the mutable nature of objects. Unlike primitives (strings, numbers, booleans, etc.) objects are subject to modification.
Consider this simple example:
In this example, both solarSystem and homeSystem point to the same underlying object. And when the number of planets is modified, that is reflected in both variables....

When working with dates, one of a programmer's most common needs is to check whether one date matches another. And if you're like most programmers, the first way that you thought of doing it is something like this:
Unfortunately, this function will never return true....