CODEWITHSUNDEEP
javascript
Cheetah
Cheetah

Reputation: 14379

Why has window and document been passed as parameters?

Modernizr starts with the following: 

window.Modernizr = (function(window,document,undefined) { ...

...but why have window and document been passed as parameters? Is it something to do with differences between browsers? Or is it simply so the can't be redefined?

Upvotes: 1

Views: 75

Answers (2)

ThiefMaster
ThiefMaster

Reputation: 318488

The parameters when calling that function are the following: (this, this.document) So it's guaranteed that window is the global object, document is the document object and undefined is undefined.

It also results in a small performance improvement; see Why does jQuery has a "window=this" at the very begining and say it would speed up references to window? for details

Upvotes: 2

Madara's Ghost
Madara's Ghost

Reputation: 174957

I believe it's for efficiently. window and document don't have to be fetched every time Modernizr needs it, but rather, a cached version of it.

Upvotes: 0

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