Array iteration benchmarks

PHP kode 

 <?php
 $range = range(0, 100000);
 $result = array();
 
 $fn = function(&$item, $k = null) use ($result) {
     if(($pos = strpos($item, ':')) !== false) {
         $result[substr($item, $pos+1)] = 1;
     }
 };
 $fn2 = function(&$item) use ($result)  {
     if(($pos = strpos($item, ':')) !== false) {
         $result[substr($item, $pos+1)] = 1;
     }
 };
 $fn3 = function(Iterator $iterator) use ($result) {
     $item = $iterator->current();
     if(($pos = strpos($item, ':')) !== false) {
         $result[substr($item, $pos+1)] = 1;
     }
     return true;
 };
 
 echo 'array_map()<br />';
 $result = array();
 $start = microtime(true);
 array_map($fn2, $range);
 echo 'time: '. round(microtime(true)-$start,4).' mem: '.round(memory_get_usage(true)/1048576,2).'<br /><br />';
 
 
 echo 'array_walk()<br />';
 $result = array();
 $start = microtime(true);
 array_walk($range, $fn);
 echo 'time: '. round(microtime(true)-$start,4).' mem: '.round(memory_get_usage(true)/1048576,2).'<br /><br />';
 
 
 echo 'iterator_apply()<br />';
 $result = array();
 $start = microtime(true);
 $it = new ArrayIterator($range);
 iterator_apply($it, $fn3, array($it));
 echo 'time: '. round(microtime(true)-$start,4).' mem: '.round(memory_get_usage(true)/1048576,2).'<br /><br />';
 
 
 echo 'foreach() with function<br />';
 $result = array();
 $start = microtime(true);
 foreach($range as $item) {
     $fn2($item);
 }
 echo 'time: '. round(microtime(true)-$start,4).' mem: '.round(memory_get_usage(true)/1048576,2).'<br /><br />';
 
 
 
 echo 'foreach()<br />';
 $result = array();
 $start = microtime(true);
 foreach($range as $item) {
     if(($pos = strpos($item, ':')) !== false) {
         $result[substr($item, $pos+1)] = 1;
     }
 }
 echo 'time: '. round(microtime(true)-$start,4).' mem: '.round(memory_get_usage(true)/1048576,2).'<br /><br />';

Kode 

array_map()
time: 0.2703 mem: 12

array_walk()
time: 0.1578 mem: 12

iterator_apply()
time: 0.2354 mem: 17.75

foreach() with function
time: 0.1329 mem: 17.75

foreach()
time: 0.093 mem: 17.75