How to return control from callback function or break the processing of array in middle array_filter processing

Question

Can we break execution of callback once condition satisfied with one element of array?

ex .

$a = array(1,2,3,4,5);
foreach($a as $val){

    if ($val == 3){
      break;
    }

}

if we write call back for it, it will be as below

$result = array_filter($a, function(){
      if ($val == 3){
          return true;
        }
});

In callback it will go through all array element, in spite of condition is being satisfied at 3. rest two elements 4, 5 will also go through callback

I want such function in callback, which will break callback one desired condition match and stop execution of rest of elements

Is is possible?

Answer 1

You can do that with a static variable. A static variable is of local scope inside the callback function but preserves its value between calls.

It behaves like a global variable in terms of its value, but with a local scope:

$callback = function($val)
{
    static $filter = false;

    if ($val == 3) {
        $filter = true;
    }

    return $filter;        
};

This callback will return false until $val == 3. It then will return true.

Answer 2

I dont think you can achieve this with array_filter, but you can do something like this:

$a = array(1,2,3,4,5);
try {
    array_walk($a, function($value, $key) use(&$a) {
        if ($value == 3){
            throw new Exception("condition match");
        }
        unset($a[$key]);
    });
}
catch(Exception $e) { }
var_dump($a);