Today I stumbled on two articles about Javascript dos and don’ts. Most
of it is common sense and practiques you develop naturally if you mean
it seriously with Javascript. However there were a couple of tricks
that caught my attention.
1. Smart looping through an array of elements:
var rows = document.getElementsByTagName('tr'); for( var i = 0, row; row = rows[i]; i++ ) { // do stuff with rows here }
2. Reduce reflow.
3. Cache complex objects:
var cached = (function () { var privateObj = { option1: 500, option2: 1000 }; return function (arg) { // foo(); }; })();
Now you can do
cached()
which will have access to the variables defined in the privateObj. This object is created only once, hence the speed-up.