除了它是懒惰是有一个很好的理由不使用<？=来回应PHP变量？ [重复]

Question

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What is the difference between the PHP open tags “<?=” and “<?php”/“<?”?

Rather than type:

<?php echo $foo; ?>

I have seen it written

<?= $foo; ?>

But I've often wondered what the risk/impracticalities are of doing it? Just curious. Thanks!

Answer 1

If you happen to move the code to an environment where short_open_tag isn't enabled, you'll be exposing a lot of internal variable names (security issue) and have a whole lot of damaged output.

The other downside is that the same setting that allows usage of <?= is the same that lets you open PHP tags with just <?, so having it disabled would not only expose those specific variables you were attempting to display, but also display any PHP code within short tags.