endforeach 在循环中? [英] endforeach in loops?

问题描述

我在使用 foreach 循环时使用括号.endforeach 有什么用?

I use brackets when using foreach loops. What is endforeach for?

推荐答案

主要是为了让你在循环中创建 HTML 时开始和结束语句更清晰:

It's mainly so you can make start and end statements clearer when creating HTML in loops:

<table>
<? while ($record = mysql_fetch_assoc($rs)): ?>
    <? if (!$record['deleted']): ?>
        <tr>
        <? foreach ($display_fields as $field): ?>
            <td><?= $record[$field] ?></td>
        <? endforeach; ?>
        <td>
        <select name="action" onChange="submit">
        <? foreach ($actions as $action): ?>
            <option value="<?= $action ?>"><?= $action ?>
        <? endforeach; ?>
        </td>
        </tr>
    <? else: ?>
         <tr><td colspan="<?= array_count($display_fields) ?>"><i>record <?= $record['id'] ?> has been deleted</i></td></tr>
    <? endif; ?>
<? endwhile; ?>
</table>

对比

<table>
<? while ($record = mysql_fetch_assoc($rs)) { ?>
    <? if (!$record['deleted']) { ?>
        <tr>
        <? foreach ($display_fields as $field) { ?>
            <td><?= $record[$field] ?></td>
        <? } ?>
        <td>
        <select name="action" onChange="submit">
        <? foreach ($actions as $action) { ?>
            <option value="<?= $action ?>"><?= action ?>
        <? } ?>
        </td>
        </tr>
    <? } else { ?>
         <tr><td colspan="<?= array_count($display_fields) ?>"><i>record <?= $record['id'] ?> has been deleted</i></td></tr>
    <? } ?>
<? } ?>
</table>

希望我的例子足以证明，一旦你有多层嵌套循环，缩进就会被所有的 PHP 打开/关闭标签和包含的 HTML 抛出(也许你必须以某种方式缩进 HTML以您想要的方式获取页面)，替代语法(endforeach) 形式可以让你的大脑更容易解析.使用正常样式，结束 } 可以单独留下，并且很难分辨它们实际关闭的内容.

Hopefully my example is sufficient to demonstrate that once you have several layers of nested loops, and the indenting is thrown off by all the PHP open/close tags and the contained HTML (and maybe you have to indent the HTML a certain way to get your page the way you want), the alternate syntax (endforeach) form can make things easier for your brain to parse. With the normal style, the closing } can be left on their own and make it hard to tell what they're actually closing.

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