Can't remove empty elements from array

Question

I want to remove empty elements from an array. I have a $_POST-String which is set to an array by explode(). Then I'am using a loop to remove the empty elements. But that does not work. I also tried array_filter(), but with no succes. Can you help me? See Code below:

$cluster = explode("\n", $_POST[$nr]);

     print_r ($cluster);
     echo "<br>";

  for ($i=0 ; $i<=count($cluster);$i++) 
    {
      if ($cluster[$i] == '') 
       {
         unset ( $cluster[$i] );
       }
    }

     print_r ($cluster);
     echo "<br>";

Result:

Array ( [0] => Titel1 [1] => Titel2 [2] => Titel3 [3] => [4] => [5] => )

Array ( [0] => Titel1 [1] => Titel2 [2] => Titel3 [3] => [4] => )

we cant really see what you're empty elements are

jon_darkstar
– jon_darkstar

2011-04-08 19:02:06 +00:00
Commented Apr 8, 2011 at 19:02 — jon_darkstar
– jon_darkstar, Commented Apr 8, 2011 at 19:02

user142162 · Accepted Answer · 2011-04-08 19:00:50Z

4

Empty elements can easily be removed with array_filter:

$array = array_filter($array);

Example:

$array = array('item_1' => 'hello', 'item_2' => '', 'item_3' => 'world', 'item_4' => '');
$array = array_filter($array);
/*
Array
(
    [item_1] => hello
    [item_3] => world
)
*/

answered Apr 8, 2011 at 19:00

user142162

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3 Comments

user142162 Over a year ago

@teuneboon: He didn't post the code for that attempt, so it's possible he/she make a mistake.

jon_darkstar Over a year ago

cool, i was about to post array_filter(function($x){return $x;}, $_POST[$nr]); but i didnt realize there was a 'default' function like that

understack Over a year ago

if integer 0 is a valid value, then see this : stackoverflow.com/questions/3654295/remove-empty-array-elements/…. By default array_filter would remove all 0/False/null/''. See this : php.net/manual/en/function.array-filter.php#example-4111

dog · Accepted Answer · 2011-04-08 19:08:20Z

1

The problem ist that the for loop condition gets evaluated on every run.

That means count(...) will be called multiple times and every time the array shrinks.

The correct way to do this is:

$test = explode("/","this/is/example///");
print_r($test);
$arrayElements = count($test);
for($i=0;$i<$arrayElements;$i++)
    if(empty($test[$i])
        unset($test[$i]);

print_r($test);

An alternative way without an extra variable would be counting backwards:

$test = explode("/","this/is/example///");
print_r($test);
for($i=count($test)-1;$i>=0;$i--)
    if(empty($test[$i])
        unset($test[$i]);

print_r($test);

answered Apr 8, 2011 at 19:08

dog

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1 Comment

Crayl Over a year ago

Thanks. I've now solved this with trim & a while loop $i = 0; $v = count($cluster); while ( $i<$v) { if (trim($cluster[$i]) == '') { unset ( $cluster[$i] ); } $i++; }

teuneboon · Accepted Answer · 2011-04-08 18:59:58Z

1

What if you change:

for ($i=0 ; $i<=count($cluster);$i++) { if ($cluster[$i] == '') { unset ( $cluster[$i] ); } }

to

for ($i=0 ; $i<=count($cluster);$i++) { if (trim($cluster[$i]) == '') { unset ( $cluster[$i] ); } }

answered Apr 8, 2011 at 18:59

teuneboon

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2 Comments

Crayl Over a year ago

Awesome. Thanks for the fast answer!

Crayl Over a year ago

Result is with that: Array ( [0] => Test1 [1] => Test2 [2] => [3] => [4] => [5] => ) <br/> Array ( [0] => Test1 [1] => Test2 [5] => )

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