Why doesn't PHP catch a “Class not found” error?

Question

In the following example, if the class does not exist, I want to catch the error and create a Null class instead.

But in spite of my try/catch statement

Answer 1

Because php emits fatal error when you ty to create new object of non existing class. To make it work you will need php >= 5.3 and autoload function, where you should try to look for file with class definition or throw your custom exception.

Answer 2

You need to use class_exists to see if the class exists before you try and instantiate it.

Incidentally, if you're using a class autoloader, be sure to set the second arg to true.

Answer 3

php >= 7.0

php can catch 'class not found' as Throwable

try {
        return new $className($smartFormIdCode);
} catch (\Throwable $ex) {
        return new SmartFormNull($smartformIdCode);
}

Answer 4

Because it's a fatal error. Use class_exists() function to check if class exist.

Also: PHP is not Java - unless you redefined default error handler, it will raise errors and not throw exceptions.

Answer 5

Old question, but in PHP7 this is a catchable exception. Though I still think the class_exists($class) is a more explicit way to do it. However, you could do a try/catch block using the new \Throwable exception type:

$className = 'SmartForm' . $smartFormIdCode;
try {
    return new $className($smartFormIdCode);
} catch (\Throwable $ex) {
    return new SmartFormNull($smartformIdCode);
}