donglong2856 2012-05-11 21:08
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foreach循环循环一次在空数组,bug?

I've found weird behaviour in PHPs foreach loop. When I do it like this:

<?php
$arr = array();

foreach ( $arr as $a )
{
    echo 'Hello';
}
?>

Then as I expect, nothing is printed simply because the array is empty, but when I do it like this:

<? $arr = array(); ?>

<? foreach ( $arr as $a ): ?>
    Hello
<? endforeach; ?>

Then the word 'Hello' is printed once... Even though the array is empty. I don't see why this would behave differently. To me this looks like a bug, but I could be missing something...

I'm using PHP 5.4 (Windows).

And in case you're wondering, I'm using the second method in my .phtml files (template files).

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  • duanlian1320 2012-05-11 21:15
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    I did some tests, and it seems this is happening because short_open_tag is off.

    You're seeing "Hello" because the PHP is not being ran.

    You need to edit your php.ini and set short_open_tag to 1.

    As of PHP 5.4, the <?php echo alias <?= is always available, but the short tag (<?) syntax still needs that option set.

    Docs: http://www.php.net/manual/en/ini.core.php#ini.short-open-tag

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