how to check a variable is NULL ?

[garcon]

$facility_id = $_POST["facility_id"];
if($facility_id == NULL) echo "new";
else echo $facility_id;

 

Why does the above code never echo new? Tis confusing me. I can post code more in full if needed. I've also tried if(!$facility_id)

[rsammy]

try this:

if($facility_id == '') echo "new";

[dmccabe]

Can you do it this way too:

 

if (!$facility_id) { echo "new"; }

 

?

 

Nto saying you, but rather asking if that is the same thing?

 

[rsammy]

if $facility_id is NULL, it may sometimes contain a blank space. if this is the case, then

if (!$facility_id) { echo "new"; }

may not work as blank space is still considered a value. i may be wrong, but i've faced this before. i therefore play it safe by comparing with a blank space

[discomatt]

You can use empty() or !$varname to check if it's NULL, empty, or not defined.

 

If you want to check for null specifically, try $varname === NULL;

 

<?php

$var = NULL;

if ($var === NULL)
    echo 'works';

?>

 

echo'ed 'works' for me.

[discomatt]

Also, try this:

 

echo '(' . $_POST["facility_id"] . ')';

 

and copy the results in your source to here. It should return '()' if it is NULL, empty, or undefined.

[garcon]

I've solved it by making sure that $facility_id won't ever be NULL and instead is 0 now.

 

Cheers for the help