Why do I need the isset() function in php?

Posted by Chris on Stack Overflow See other posts from Stack Overflow or by Chris
Published on 2010-03-17T06:36:21Z Indexed on 2010/03/17 6:41 UTC
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Filed under:

php

|

isset

|

post

|

if-statement

I am trying to understand the difference between this:

if (isset($_POST['Submit'])) { 
  //do something
}

and

if ($_POST['Submit']) { 
  //do something
}

It seems to me that if the $_POST['Submit'] variable is true, then it is set. Why would I need the isset() function in this case?

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