如何使這樣的：這個從數組的數組轉換爲單一陣列
array(2) {
[0] => array(1) {
["bleh"] => int(109720)
}
[1] => array(1) {
["bleh"] => int(112439)
}
}
最有效？
array(2) {
0 => 109720,
1 => 112439
}
我不能按照下面konforces答案的評論給出的尺寸，但是這一個是最低限度的速度比在foreach使用裁判：
$c=count($array);
for(
$i=0;
$i<$c
;
$array[$i]=$array[$i]['bleh'],
$i++
);
韓元並不是說實際衡量它是微不足道的，時間變化取決於哪一個是第一個，這是根據這個問題有一千萬成員的數組：
foreach ref: 4.192161
foreach key: 4.383342
foreach copy: 4.222771
array_map lambda: 12.240275
array_map reset: 16.401093
for key: 3.459406
for copy: 4.690722
腳本：
ini_set('memory_limit', -1); // wer're going to consume a lot.
$arrayCount = 10000000;
$test = 'just run';
$array = array_fill(0, $arrayCount, array("bleh" => 109720,));
$array = end($array);
$array = array_fill(0, $arrayCount, array("bleh" => 109720,));
$array = array_map(function(){}, $array);
$test = 'foreach ref';
$array = array_fill(0, $arrayCount, array("bleh" => 109720,));
$start = microtime(1);
foreach($array as &$v) $v = $v['bleh'];
unset($v);
$diff = microtime(1)-$start;
$tests[$test] = $diff;
printf("%s: %f\n", $test, $diff);
$test = 'foreach key';
$array = array_fill(0, $arrayCount, array("bleh" => 109720,));
$start = microtime(1);
foreach($array as $k => $v) $array[$k] = $v['bleh'];
$diff = microtime(1)-$start;
$tests[$test] = $diff;
printf("%s: %f\n", $test, $diff);
$test = 'foreach copy';
$array = array_fill(0, $arrayCount, array("bleh" => 109720,));
$start = microtime(1);
foreach($array as $k => $v) $arrayb[] = $v['bleh'];
$diff = microtime(1)-$start;
$tests[$test] = $diff;
unset($arrayb);
printf("%s: %f\n", $test, $diff);
$test = 'array_map lambda';
$array = array_fill(0, $arrayCount, array("bleh" => 109720,));
$start = microtime(1);
$array = array_map(function($e) { return $e['bleh']; }, $array);
$diff = microtime(1)-$start;
$tests[$test] = $diff;
printf("%s: %f\n", $test, $diff);
$test = 'array_map reset';
$array = array_fill(0, $arrayCount, array("bleh" => 109720,));
$start = microtime(1);
$array = array_map('reset', $array);
foreach($array as $k => $v) $arrayb[] = $v['bleh'];
$diff = microtime(1)-$start;
$tests[$test] = $diff;
printf("%s: %f\n", $test, $diff);
$test = 'for key';
$array = array_fill(0, $arrayCount, array("bleh" => 109720,));
$start = microtime(1);
for($i=0,$c=count($array);$i<$c;$array[$i]=$array[$i]['bleh'],++$i);
$diff = microtime(1)-$start;
$tests[$test] = $diff;
printf("%s: %f\n", $test, $diff);
$test = 'for copy';
$array = array_fill(0, $arrayCount, array("bleh" => 109720,));
$start = microtime(1);
for($i=0,$c=count($array);$i<$c;$arrayb[]=$array[$i]['bleh'],++$i);
$diff = microtime(1)-$start;
$tests[$test] = $diff;
unset($arrayb);
printf("%s: %f\n", $test, $diff);
如果你需要一個快速的解決方案（良好的執行速度），那麼：
$a = /* the original array */;
$b = array();
foreach ($a as $value) {
$b[] = $value['bleh'];
}
使用array_map。
$a = array_map(function($e) { return $e['bleh']; }, $a);
嘗試reset
$result = array_map("reset", $a);
<?php
$all = array(
array("one" => 1),
array("two" => 2),
array("three" => 3)
);
function getKey($item)
{
return key($item);
}
function getVal($item)
{
return $item[key($item)];
}
$keys = array_map("getKey", $all);
$values = array_map("getVal", $all);
print_r($keys);
print_r($values);
OUTPUT:
Array (
[0] => one
[1] => two
[2] => three)
Array (
[0] => 1
[1] => 2
[2] => 3)
精湛而深入的答案 – FinalForm