Using underscore (_) as a PHP function name

Question

According to http://php.net/manual/en/functions.user-defined.php, I should be able to use an underscore (_) as a function name: Function names follow the same rules as other labels in PHP. A valid function name starts with a letter or underscore, followed by any number of letters, numbers, or underscores. As a regular expression, it would be expressed thus: [a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*. However, the following kills my program without causing any errors: ``` error_reporting(E_ALL); echo('start'); function _($x){return ($x)?htmlspecialchars($x):'nbsp;';} echo('end'); ``` I am using PHP Version 5.3.18. What don't I understand?

Accepted Answer

There is already a built-in function called `_`; it is an alias for `gettext`.

You are likely getting a `Fatal error: Cannot redeclare _()`, but the error may not be output to your screen depending on your setting for `display_errors`. You could also look at the `log_errors` directive.

Using underscore (_) as a PHP function name

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