Esempio 19-39. Type Hinting example
<?php // An example class class MyClass { /** * A test function * * First parameter must be an object of type OtherClass */ public function test(OtherClass $otherclass) { echo $otherclass->var; } }
// Another example class class OtherClass { public $var = 'Hello World'; } ?>
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Failing to satisfy the type hint results in a fatal error.
<?php // An instance of each class $myclass = new MyClass; $otherclass = new OtherClass;
// Fatal Error: Argument 1 must be an object of class OtherClass $myclass->test('hello');
// Fatal Error: Argument 1 must be an instance of OtherClass $foo = new stdClass; $myclass->test($foo);
// Fatal Error: Argument 1 must not be null $myclass->test(null);
// Works: Prints Hello World $myclass->test($otherclass); ?>
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Type hinting also works with functions:
<?php // An example class class MyClass { public $var = 'Hello World'; }
/** * A test function * * First parameter must be an object of type MyClass */ function MyFunction (MyClass $foo) { echo $foo->var; }
// Works $myclass = new MyClass; MyFunction($myclass); ?>
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