php array remove empty values recursive

<?php
$arr = array('1', '', '2', '3', '0');
// Incorrect:
print_r(array_filter($arr));
// Correct:
print_r(array_filter($arr, 'strlen'));
//Custom
print_r(array_filter($arr, function ($val) {if ($val > 0) {return true;} else {return false;}}));

array_filter(explode('/', '/home/teste sdsd/   /'), 'trim');
//Result
[
     1 => "home",
     2 => "teste sdsd",
]

//-----------
array_filter(explode('/', '/home/teste sdsd/   /'), 'strlen')
//Result
  [
     1 => "home",
     2 => "teste sdsd",
     3 => "   ",
   ]