PHP Array_Filter with Arguments

PHP array_filter with arguments

As an alternative to @Charles's solution using closures, you can actually find an example in the comments on the documentation page. The idea is that you create an object with the desired state ($num) and the callback method (taking $i as an argument):

class LowerThanFilter {
        private $num;

        function __construct($num) {
                $this->num = $num;
        }

        function isLower($i) {
                return $i < $this->num;
        }
}

Usage (demo):

$arr = array(7, 8, 9, 10, 11, 12, 13);
$matches = array_filter($arr, array(new LowerThanFilter(12), 'isLower'));
print_r($matches);

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As a sidenote, you can now replace LowerThanFilter with a more generic NumericComparisonFilter with methods like isLower, isGreater, isEqual etc. Just a thought — and a demo...

php array filter with custom arguments

Use an anonymous function instead of a defined function if you want to pass values into the scope of the callback.

array_filter($your_array, function($element) use ($action, $url) {
    return isset($element->action, $element->url)
        && $element->action == $action
        && $element->url == $url;
});

PHP array_filter with argument to callback

I got it to work using an object, http://www.php.net/manual/en/language.pseudo-types.php#language.types.callback

class univFilter {
    public $univ_seg;
    public function filter($var) {
        if($var["EventType"] == "UN" && $var["LocationURL"] == $this->univ_seg)
            return true;
          else
            return false;
    }
}

$data = json_encode(Array(
    Array("StartDate"=>"2014/07/31","LocZipCode"=>"19406","LocationURL"=>"FSU","EventType"=>"UN"),
    Array("StartDate"=>"2014/08/31","LocZipCode"=>"23513","LocationURL"=>"FSU","EventType"=>"UN"),
    Array("StartDate"=>"2014/11/30","LocZipCode"=>"92108","LocationURL"=>"BU","EventType"=>"UN"),
    Array("StartDate"=>"2014/09/30","LocZipCode"=>"78661","LocationURL"=>"BU","EventType"=>"UN")
));

$univ_seg = "BU";
getUA($data,$univ_seg);

function getUA($data, $univ_seg) {
    $f = new univFilter();
    $f->univ_seg = $univ_seg;
    $univ_sched = json_decode($data, true);
    $data       = array_filter($univ_sched,array($f,"filter"));
    print_r($data);
}

is it possible if callback in array_filter receive parameter?

You can create a closure on PHP ≥5.3.

array_filter($files, function($array) use ($key) {
  return is_inarr_key($array, $key); 
} );

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If you are stuck with PHP <5.3, …

You can make $key a global variable.

function is_inarr_with_global_key($array) {
   global $key;
   ....
}

You can create a class

class KeyFilter {
  function KeyFilter($key) { $this->key = $key; }
  function is_inarr_key($array) { ... }
}
...
array_filter($files, array(new KeyFilter('name'), 'is_inarr_key'));

You can create 3 different functions

array_filter($files, 'is_inarr_name');
array_filter($files, 'is_inarr_path');
array_filter($files, 'is_inarr_number');

You can write your own array_filter

function my_array_filter($files, $key) {
  ...
}

Use external variable in array_filter

The variable $id isn't in the scope of the function. You need to use the use clause to make external variables accessible:

$foo = array_filter($bar, function($obj) use ($id) {
    if (isset($obj->foo)) {
        var_dump($id);
        if ($obj->foo == $id) return true;
    }
    return false;
});

What is the default value for callback argument of array_filter function

If the source code of array_filter contains a second parameter, it is checked whether it is a real callable function. A string can also be passed. But even then it is checked whether this is a real function.

Variant 1: Define a function, then use its name

function isNotEmpty($val){
  return !empty($val);
}

$arr = [0,1,[],null,false,"a","",(object)[],-1];

$res = array_filter( $arr);
$res1 = array_filter( $arr, 'isNotEmpty');
    
var_dump($res === $res1); //bool(true)

Variant 2: Use the boolval function

$arr = [0,1,[],null,false,"a","",(object)[],-1];

$res = array_filter( $arr);
$res1 = array_filter( $arr, 'boolval');

var_dump($res === $res1);  //bool(true)

With the function boolvar () this also works apparently. However, the PHP manual says:

var The scalar value being converted to a bool.

But the examples for the boolval function also show an empty array as a value.

Correct syntax for php array_filter?

Seems like missing use keyword. Try this:

$all_together = array_filter($info, function($each_one) use ($extra) {
    $op = $each_one["something"];
    if($op <= $extra) return $each_one["what_I_need"];
});

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