I have an array
Array ( [0] => 0 [1] => [2] => 3 [3] => )
i want to remove null values from this and the result should be like this
Array ( [0] => 0 [1] => 3) i don't want to remove 0 value from array.
2
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php.net/array_filter with custom callback.Cthulhu– Cthulhu2013-12-19 08:35:32 +00:00Commented Dec 19, 2013 at 8:35
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on php.net look up array filterNick Maroulis– Nick Maroulis2013-12-19 08:35:43 +00:00Commented Dec 19, 2013 at 8:35
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6 Answers
this will do the trick:
array_filter($arr, static function($var){return $var !== null;} );
Code Example: https://3v4l.org/jtQa2
for older versions (php<5.3):
function is_not_null ($var) { return !is_null($var); }
$filtered = array_filter($arr, 'is_not_null');
Code Example: http://3v4l.org/CKrYO
7 Comments
Edgar Klerks
Only works in newer versions, but this is way better than the strange strlen thing.
Cthulhu
For older versions one can predeclare the function used.
AlexP
You can exclude the second param entirely;
array_filter($arr); will remove null by default.
jko
@AlexP nope, you are wrong. as seen on 3v4l.org/Y9KCX your solution would remove everything that is
empty() - not just NULL.
mercredo
@AlexP: a string '0' for instance will be removed, if you dismiss filter function.
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You can use array_filter() which will get rid of the null empty values from the array
print_r(array_filter($arr, 'strlen'));
5 Comments
Rob
This does not work. $ php -r "var_dump(array_filter([0, null, false, 'hi', ''], 'strlen'));" array(2) { [0] => int(0) [3] => string(2) "hi" }
Gokigooooks
this also removes '0', false, or falsey values in general might have forgotten others.
Nizar Blond
this will include '' which is not null
OMA
You can even do $arr = array_filter($arr); with no callback and it will still remove empty items.
mickmackusa
From PHP8.1 this is no longer a good technique because it will generate Deprecations.
Deprecated: strlen(): Passing null to parameter #1 ($string) of type string is deprecatedYou can just loop through it.
<?php
foreach ($array as $i=>$row) {
if ($row === null)
unset($array[$i]);
}
If you want to reindex the array to remove gaps between keys, you can just use a new array:
<?php
$array2 = array();
foreach ($array as $row) {
if ($row !== null)
$array2[] = $row;
}
$array = $array2;
Comments
You are in a world of trouble now, because it is not too easy to distinguish null from 0 from false from "" from 0.0. But don't worry, it is solvable:
$result = array_filter( $array, 'strlen' );
Which is horrible by itself, but seems to work.
EDIT:
This is bad advice, because the trick leans on a strange corner case:
- strlen(0) will be strlen("0") -> 1, thus true
- strlen(NULL) will be strlen("")->0, thus false
- strlen("") will be strlen(("")->0, thus false etc.
The way you should do it is something like this:
$my_array = array(2, "a", null, 2.5, NULL, 0, "", 8);
function is_notnull($v) {
return !is_null($v);
}
print_r(array_filter($my_array, "is_notnull"));
This is well readable.
1 Comment
mickmackusa
From PHP8.1
strlen is no longer a good technique because it will generate Deprecations. Deprecated: strlen(): Passing null to parameter #1 ($string) of type string is deprecated<?php
$arr = array( 0 => 0, 1=>null, 2=>3, 3=>null);
foreach ($arr as $key=>$val) {
if ($val === null)
unset($arr[$key]);
}
$new_arr = array_values($arr);
print_r($new_arr);
?>
Out put:
Array
(
[0] => 0
[1] => 3
)
Comments
simply
$keys=array_keys($yourArray,NULL);
if(!empty($keys))
{
foreach($keys as $key)
{
unset($yourArray[$key]);
}
}
var_dump($yourarray);
