PHP Judgment class whether there is function class_exists usage analysis, function class_exists_php tutorial

PHP Judgment class whether there is function class_exists usage analysis, function class_exists

This paper analyzes the existence of function class_exists usage of PHP judgment class. Share to everyone for your reference. Specific as follows:

If we want to determine whether a class is available, you can use the Class_exists function first to judge, here are a few examples.

BOOL Class_exists (String $class _name [, bool $autoload = True])
Whether the given class is defined by this feature is checked. This function checks whether, or not, the given class has been defined.
Returns True if Class_name is a defined class, otherwise returns FALSE.

Examples are as follows:

Copy the Code code as follows: function __autoload ($class)
{
Include ($class. '. php ');
Check to see whether the include declared the class
if (!class_exists ($class, false)) {
Trigger_error ("Unable to load class: $class", e_user_warning);
}
}
if (class_exists (' MyClass ')) {
$myclass = new MyClass ();
}

I hope this article is helpful to everyone's PHP programming.

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