Filter out negative integers from an array PHP

Question

I'm trying to remove all negative integers from the following array :

$array = array([-122,121,-124,124,-121,122,-122,124,-121,124,-122,125,-121,121,-123,122,-124,120]);

I've tried the following, it's not working as I don't really understand how array_filter works :

function positive($var) {
  if ($var >= 0) {
    return $var;
  }
}

print_r(array_filter($array, positive($var)));

How would I send each value to the positive function? Or is there a better way of doing this? array_walk or array_map maybe?

Answer 1

Use this code:

<?php
$array = array([-122,121,-124,124,-121,122,-122,124,-121,124,-122,125,-121,121,-123,122,-124,120]);

function positive($var) 
{
    if ($var >= 0) 
    {
        return true;
    }
}

print_r(array_filter($array[0], 'positive'));

You had to pass $array[0] as parameter to modify array. You have declared array with array in first element array([-122,...,-124,120]); so to filter array you need to pass $array[0].

Output is:

Array ( [1] => 121 [3] => 124 [5] => 122 [7] => 124 [9] => 124 [11] => 125 [13] => 121 [15] => 122 [17] => 120 )