What does this expression mean "!!"

Posted by Alex on Stack Overflow See other posts from Stack Overflow or by Alex
Published on 2010-06-17T07:06:16Z Indexed on 2010/06/17 7:13 UTC
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JavaScript

Why would somebody use an expression like

var obj = {};
if(!!obj) alert('exists');

instead of just

if(obj) alert('exists');

?

Is there another usage for the "!!" thing ?

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Developer IT

What does this expression mean "!!" - Developer IT

What does this expression mean "!!"

JavaScript

Related posts about JavaScript

CHAT ROOMs 7 by 6

Integrating JavaScript Unit Tests with Visual Studio

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PHP, javascript, single quote problems with IE when passing variable from ajax post to javascript fu

Javascript in XSL that is loaded by Javascript

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