dongyan8929 2011-02-15 04:11
浏览 26
已采纳

PHP foreach(...)问题

I was wondering if using

foreach(get_some_array() as $boo) do_something...

is slower than

$arr = get_some_array();
foreach($arr as $boo) do_something...

I mean would get_some_array() be called like 10000000 times if the array would have so many elements (in the 1st example) ?

  • 写回答

2条回答 默认 最新

  • dragonfly9527 2011-02-15 04:16
    关注

    No, that function will be called just 1 time. You can verify this by doing:

    <?php
    function get()
    {
        echo "getting
    ";
    
        return array('a', 'b', 'c', 'd');
    }
    
    foreach (get() as $v) {
        echo $v . "
    ";
    }
    ?>
    

    Here it outputs:

    murilo@mac:regionais$ php -f teste.php 
    getting
    a
    b
    c
    d
    
    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论
查看更多回答(1条)

报告相同问题?

悬赏问题

  • ¥15 Vue3 大型图片数据拖动排序
  • ¥15 划分vlan后不通了
  • ¥15 GDI处理通道视频时总是带有白色锯齿
  • ¥20 用雷电模拟器安装百达屋apk一直闪退
  • ¥15 算能科技20240506咨询(拒绝大模型回答)
  • ¥15 自适应 AR 模型 参数估计Matlab程序
  • ¥100 角动量包络面如何用MATLAB绘制
  • ¥15 merge函数占用内存过大
  • ¥15 使用EMD去噪处理RML2016数据集时候的原理
  • ¥15 神经网络预测均方误差很小 但是图像上看着差别太大