How Can I Instantiate PHP Classes Dynamically Using Strings?

Dynamic Class Instantiation with Strings in PHP

In PHP, it is possible to create an instance of a class using a string representing the class name. This eliminates the need for lengthy switch statements when dealing with multiple classes.

Consider the following example:

class ClassOne {}
class ClassTwo {}

$str = 'One';

Rather than using a switch statement:

switch ($str) {
    case "One":
        $object = new ClassOne();
        break;
    case "Two":
        $object = new ClassTwo();
        break;
}

You can dynamically create an instance using a string as follows:

$class = 'Class' . $str;
$object = new $class();

This syntax constructs the full class name (e.g., "ClassOne") and instantiates it. If your classes are in namespaces, use the fully qualified name:

$class = '\Foo\Bar\MyClass';
$instance = new $class();

PHP extends this capability to variable functions and methods as well:

$func = 'my_function';
$func(...$parameters); // Calls my_function() with parameters

$method = 'doStuff';
$object = new MyClass();
$object->$method(); // Calls Myclass->doStuff()
(new MyClass())->$method(); // Calls Myclass->doStuff() in one line

While you can create variables with strings, it is considered bad practice and should be avoided in favor of using arrays.

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