javascript undefined compare

Posted by nahum on Stack Overflow See other posts from Stack Overflow or by nahum
Published on 2010-05-06T06:23:38Z Indexed on 2010/05/06 6:38 UTC
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undefined

Ok here is my question in javascript you can declare a variable and be undefined you can apply variable == undefined, I know that but how you can compare a value that you dont know yet if it's in the cpu memory. I have a class which is create it when the user click on a button. before this the class is undefined there no exist in any where so how can I compare it? without using try{}catch(e){} is there a way????

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