Comments on: Remove NULL values from PHP arrays with 1 line

By: Remove NULL values from PHP arrays with 1 line « PHP Code Search

Remove NULL values from PHP arrays with 1 line « PHP Code Search — Wed, 01 Sep 2010 09:29:28 +0000

[...] Thanks to http://briancray.com/2009/04/25/remove-null-values-php-arrays/ [...]

By: NXie

NXie — Thu, 24 Jun 2010 02:10:17 +0000

Nice job. Exactly what I was looking for.

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By: David

David — Mon, 27 Jul 2009 08:38:28 +0000

is_scalar will work for Cometbus’ sample array.

By: Brian Cray

Brian Cray — Mon, 27 Apr 2009 18:26:03 +0000

Cometbus:

You’re right about that. I added my original code for this tutorial, which removes ONLY NULL values.

By: Cometbus

Cometbus — Mon, 27 Apr 2009 08:31:18 +0000

I do not see any way to do this correctly without iterating each item and explicitly unsetting each null. You could pass a unset null function to the array filter, but it is still more than one line. Maybe a regex could get it to one line.

Currently, this method is dangerous, as it will remove a lot more than just nulls…

$test_array = array('a', 'b', 'c', '1', '2', '3', null, FALSE, 0, TRUE, 1, '');


$new_array_without_nulls = array_filter($test_array);
print_r($test_array);

print_r($new_array_without_nulls);

Array ( [0] => a [1] => b [2] => c [3] => 1 [4] => 2 [5] => 3 [6] => [7] => [8] => 0 [9] => 1 [10] => 1 [11] => ) Array ( [0] => a [1] => b [2] => c [3] => 1 [4] => 2 [5] => 3 [9] => 1 [10] => 1 )

As you can see, both false and empty strings were removed. A lot of this has to do with php being a bit strange in what it calls a boolean/null/empty etc.

Not saying this is not a good thing, just that it could cause you unappreciable behavior. Arrays are often used as a place to store boolean data, and this would clobber that data on the false side of it.

By: Brian Cray

Brian Cray — Sun, 26 Apr 2009 04:40:34 +0000

Paul: Updated. Thanks so much for your valuable and obviously superior knowledge

By: Paul Scott

Paul Scott — Sun, 26 Apr 2009 04:30:36 +0000

As far as I remember, you don’t need the 2nd arg to array_filter to remove NULL values. just $array_without_nulls = array_filter($array_with_nulls); will do

By: Drew Douglass

Drew Douglass — Sat, 25 Apr 2009 17:28:07 +0000

Nice stuff Brian, I’m assuming array_map() would work similarly to array_filter() in this situation?

I’m a big fan of these quick one liners, keep them coming buddy!