array_shift vs for vs array_pop

好奇，用用array_shift  array_pop 來操做數組

 

測試，執行代碼10次，for循環執行程序10000次，查看用時，證實 for 比 shift 好太多

Shift	For	Pop
1466612647974----1466612648987 1013	1466612859942----1466612860803 861	1466612973278----1466612974312 1034
1466612661110----1466612662153 1043	1466612870539----1466612871387 848	1466612990035----1466612991084 1049
1466612672061----1466612673079 1018	1466612878459----1466612879562 1103	1466612999726----1466613000785 1059
1466612680562----1466612681612 1050	1466612886645----1466612887561 916	1466613009125----1466613010195 1070
1466612689297----1466612690332 1035	1466612893969----1466612894878 909	1466613018370----1466613019635 1265
1466612700237----1466612701437 1200	1466612903951----1466612904835 884	1466613025871----1466613026886 1015
1466612709077----1466612710098 1021	1466612912643----1466612913561 918	1466613033574----1466613034577 1003
1466612716794----1466612717832 1038	1466612921161----1466612922048 887	1466613042230----1466613043256 1026
1466612724867----1466612725907 1040	1466612928817----1466612929679 862	1466613050434----1466613051708 1274
1466612732746----1466612733797 1051	1466612936061----1466612936932 871	1466613059171----1466613060224 1053

測試代碼

.........

# array_shift       
        list($t1, $t2) = explode(' ', microtime());
        echo  $startTime = (float)sprintf('%.0f',(floatval($t1)+floatval($t2))*1000),'----';

        for($j=0; $j<10000; $j++) {


            foreach ($results as $k => $v) {
                $productNameList = explode(',', $v['product_names']);
                $productImageLocationList = explode(',', $v['product_image_location']);
                $productIdList = explode(',', $v['product_id']);
                $productSlugList = explode(',', $v['product_slug']);
                $productUnitPrice = explode(',', $v['product_unit_price']);
                $productQuantity = explode(',', $v['product_quantity']);
                $productTotalPrice = explode(',', $v['product_total_price']);

                foreach ($productNameList as $kk=>$vv) {
                    $results[$k]['product_list'][$kk] = array(
                        'product_names' => array_shift($productNameList),
                        'product_image_location' => array_shift($productImageLocationList),
                        'product_id' => array_shift($productIdList),
                        'product_slug' => array_shift($productSlugList),
                        'product_unit_price' => array_shift($productUnitPrice),
                        'product_quantity' => array_shift($productQuantity),
                        'product_total_price' => array_shift($productTotalPrice),
                    );
                }
            }
        }
        list($t1, $t2) = explode(' ', microtime());
        echo  $endTime = (float)sprintf('%.0f',(floatval($t1)+floatval($t2))*1000),"\n\r";
        echo $endTime-$startTime;
        dump($results);exit;

# for

        list($t1, $t2) = explode(' ', microtime());
        echo  $startTime = (float)sprintf('%.0f',(floatval($t1)+floatval($t2))*1000),'----';

        for($j=0; $j<10000; $j++) {


            foreach ($results as $k => $v) {
                $productNameList = explode(',', $v['product_names']);
                $productImageLocationList = explode(',', $v['product_image_location']);
                $productIdList = explode(',', $v['product_id']);
                $productSlugList = explode(',', $v['product_slug']);
                $productUnitPrice = explode(',', $v['product_unit_price']);
                $productQuantity = explode(',', $v['product_quantity']);
                $productTotalPrice = explode(',', $v['product_total_price']);

                for ($i = 0; $i < count($productNameList); $i++) {
                    $results[$k]['product_list'][$i] = array(
                        'product_names' => $productNameList[$i],
                        'product_image_location' => $productImageLocationList[$i],
                        'product_id' => $productIdList[$i],
                        'product_slug' => $productSlugList[$i],
                        'product_unit_price' => $productUnitPrice[$i],
                        'product_quantity' => $productQuantity[$i],
                        'product_total_price' => $productTotalPrice[$i],
                    );
                }
            }
        }
        list($t1, $t2) = explode(' ', microtime());
        echo  $endTime = (float)sprintf('%.0f',(floatval($t1)+floatval($t2))*1000),"\n\r";
        echo $endTime-$startTime;
        dump($results);exit;

 

# array_pop

        list($t1, $t2) = explode(' ', microtime());
        echo  $startTime = (float)sprintf('%.0f',(floatval($t1)+floatval($t2))*1000),'----';

        for($j=0; $j<10000; $j++) {


            foreach ($results as $k => $v) {
                $productNameList = explode(',', $v['product_names']);
                $productImageLocationList = explode(',', $v['product_image_location']);
                $productIdList = explode(',', $v['product_id']);
                $productSlugList = explode(',', $v['product_slug']);
                $productUnitPrice = explode(',', $v['product_unit_price']);
                $productQuantity = explode(',', $v['product_quantity']);
                $productTotalPrice = explode(',', $v['product_total_price']);

                foreach($productNameList as $kk=>$vv)
                {
                    $results[$k]['product_list'][$kk] = array(
                        'product_names'         =>      array_pop($productNameList),
                        'product_image_location'=>      array_pop($productImageLocationList),
                        'product_id'            =>      array_pop($productIdList),
                        'product_slug'          =>      array_pop($productSlugList),
                        'product_unit_price'    =>      array_pop($productUnitPrice),
                        'product_quantity'      =>      array_pop($productQuantity),
                        'product_total_price'   =>      array_pop($productTotalPrice),
                    );
                }

            }
        }
        list($t1, $t2) = explode(' ', microtime());
        echo  $endTime = (float)sprintf('%.0f',(floatval($t1)+floatval($t2))*1000),"\n\r";
        echo $endTime-$startTime;
        dump($results);exit;

         

 ........

shift 會重建數組，每次執行後，數組都會從0開始重建。形成慢的緣由，而 pop 從此次來看和shift同樣慢，對數組長度進行改變的操做會形成性能上的慢