Undefined vs window.undefined in JavaScript

Posted by eskimoblood on Stack Overflow See other posts from Stack Overflow or by eskimoblood
Published on 2010-03-30T08:16:16Z Indexed on 2010/03/30 8:33 UTC
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JavaScript

|

undefined

Can someone explain way this work

if(window.a){}

while this is failing

if(a)

In both cases a is undefined.

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