PhP5 exception handling mechanism [9]-try-catch statement

Try-catch statement

To further handle exceptions, we need to use the try-catch statement-including the try statement and at least one catch statement. Any code that calls a method that may throw an exception should use the try statement. Catch statements are used to handle exceptions that may be thrown. The following shows how we processgetCommandObject()Method for throwing an exception:

index_php5.php Second half

<?php
// PHP 5
try {
    $mgr = new CommandManager();
    $cmd = $mgr->getCommandObject('realcommand');
    $cmd->execute();
} catch (Exception $e) {
    print $e->getMessage();
    exit();
}
?>

We can see that by combining the throw keyword with the try-catch statement, we can avoid the value returned by the error mark "pollution" class method. "Exception" is a built-in PHP type that is different from any other object and will not be confused.

If an exception is thrown, the script in the try statement stops execution and immediately redirects to the script in the catch statement.

If an exception is thrown but not captured, a fatal error occurs.