Question

It appears that anon functions are objects, so I guess that the function is a method of that object. Does that mean they take more resources than a normal function?

Answer 1

I did a small test on relative run times. The script is like:

<?php
// long execution time required
ignore_user_abort(1);
set_time_limit(0);

// some presumingly costly function
function mathematics() {
  $c = 0;
  for ($i = 0; $i < 1000; $i++) $c += rand(0, 1000);
  return $c / 1000;
}

$lambda = function() {
  // same as mathematics()
};

// Executing normal function
for ($i = 0; $i < 50000; $i++) mathematics();

// Now onto lambda function
for ($i = 0; $i < 50000; $i++) $lambda();
?>

Profiling with xdebug and feeding the cache into cachegrind yields:

mathematics(): 31,804,288
closure:       31,719,438

I think it’s safe to assume that the difference in time required to run is negligeable.