3D Game Programming for Kids, 2nd Edition

The Worst Thing in JavaScript: Losing this

JavaScript is a great programming language. Except when it’s not. What happens to this in certain cases is a good example of JavaScript being not so great.

Consider using setTimeout() to call a function after a delay. We’ve done this several times in the book. In Chapter 11, ​Project: Fruit Hunt​, we used setTimeout() to shake the treasure tree after a two-second delay.

setTimeout(shakeTreasureTree, 2*1000);

After 2 seconds (2000 milliseconds), setTimeout() called our shakeTreasureTree() function. We’ve also done this several times for the gameStep() function.

setTimeout(gameStep, 1000/30);

What happens if we try to do this with our logMe() method?

setTimeout(kungFuMovie.logMe, ...