good link :wall: Note:

greg — Sat, 01 Mar 2008 18:27:46 +0000

good link :wall:

Note: Simply doing if ($x) while $x is undefined will generate an error of level E_NOTICE. Instead, consider using empty() or isset() and/or initialize your variables.

I have changed (and improved) some of my code thanks to the above. cheers.
You learn something new every day!

I just found a handy

pr0gr4mm3r — Sat, 01 Mar 2008 17:49:16 +0000

I just found a handy resource on type comparisons, thanks to StumbleUpon.

PHP type comparison tables

PHP made the change to call

pr0gr4mm3r — Mon, 25 Feb 2008 17:48:24 +0000

PHP made the change to call "0" empty in PHP4 - almost like an added feature.

Function information: http://us3.php.net/manual/en/function.empty.php

pr0gr4mm3r wrote: Well,

greg — Mon, 25 Feb 2008 07:18:01 +0000

pr0gr4mm3r wrote: Well, technically, if your bank account is at 0, it would be empty, right? Makes sense to me.

I see your point, but you wouldn't use EMPTY to check if a value is other than zero. You use IF ==0 IF<>0 etc for that.

So I disagree still with the way EMPTY is set up.
What about textual zero? It deems that to be empty too. Why? Just because a textual zero "represents" a numerical zero shouldn't make it assume empty.
That's just stupid IMHO

The number zero is a numerical value, and for PHP to determine a variable set to numerical zero to be empty is not logical.
It's not empty, it is 0.
So using EMPTY for checking user input is no good, they might be allowed and correct in entering a numerical or textual zero.

EMPTY should check if a var is empty, i.e. it contains no letters a-Z, numbers 0-9 and no other chars including space.
Then empty would determine correctly that a variable truly is EMPTY and could then be used to a much greater affect with the ISSET function.

ISSET is fine and operates as it should.
If a variable is set to be anything it is set, even blank (not even whitespace) isset will return true.

<?php
$var = ""; //no white space
isset($var) //returns true
?>

I agree with that, it has been set.

The two then would be much more useful. If you want to check if a var is empty regardless of if it was ever set or used, then use EMPTY. If you want to check if a var has ever been used or set, then use ISSET.

Currently you cannot use empty for checking results of calculations or user inputs because the input or calc might have returned zero.

So my question is this, where can EMPTY be used with confidence?
You have to use it where you are checking for user input or form calculations where a single numerical or textual zero is not expected, to be more accurate - zero will never occur.
That makes potential problems.

So even then with user input forms, telling them they did not fill in a field could be incorrect. They might have wanted their username to be a textual zero. And you should be telling them 0 is not a valid username, not they didnt type anything in.
And isset is not ueful for that because 'generally' you have something like $name = $_POST['name'];
even if the user never entered anything, isset will return true.

I know all this is managable and there are ways and means, but IMHO, EMPTY could be much more useful if it returned false for a var with zero.

I'm off to email Rasmus Lerdorf

Well, technically, if your

pr0gr4mm3r — Sun, 24 Feb 2008 20:35:56 +0000

Well, technically, if your bank account is at 0, it would be empty, right? Makes sense to me.

Yeah, I found out about that

teammatt3 — Sun, 24 Feb 2008 16:26:37 +0000

Yeah, I found out about that one the hard way. I don't like that behavior either. I use isset() a lot more because of it.