js-best-practices.md

JavaScript Best Practices

Avoid global variables

Avoid ==, use ===

Avoid eval()

Don't use new Object()

• Use {} instead of new Object()
• Use "" instead of new String()
• Use 0 instead of new Number()
• Use false instead of new Boolean()
• Use [] instead of new Array()
• Use /()/ instead of new RegExp()
• Use function() {} or () => {} instead of new Function()

let x = "John";
let y = new String("John");
(x === y) // is false

Use "use strict"

Development code is not live code

Anonymously scope JavaScript if you're never going to call it elsewhere

Performance

Excessive DOM changes

Events that get fired all the time: resizing, scrolling,...

• unbind() all event handlers before binding.

Lots of HTTP requests