Variables and Arrays - Construct 2 Game Development by Example - page 62

Variables in JavaScript
Construct 2 exports to HTML5, and this means that a lot of the functionality in the game is
written in JavaScript. In JavaScript, the type of variable is not defined until you initialize it.
While this makes programming in JavaScript much easier, it has its pros and cons. The
biggest con is that sometimes you forget which variables are of what type, which leads to
unexpected results when you run the app.