No Catch Overwrite

try ... catch is the structure designed to handle errors, emitted as Exception. Code will be run in the try block, and if some Exception is emitted, the class of the Exception will route it to the right catch block for processing.

catch blocks define an Exception type, and a variable that will hold the Exception object.

<?php

$e = 1;
try {
	/* some code */
} catch (Exception $e) {
	process($e->getMessage());
}

?>

The catch variable, here $e, will overwrite any already existing variable, if an Exception is emitted.

It is recommended to avoid overwriting variables with a catch block.

Rule Details

The following illustrate both right and wrong situations :

<?php

// $e is already defined
$e = 1;

try {
	/* some code, may be using $e too */
} catch (Exception $e) {
	// $e is wrong
	process($e->getMessage());
} catch (otherException $f) {
	// $f is OK
	process($f->getMessage());
}


?>