CODEWITHSUNDEEP
phpclassoopconstantstype-hinting
user5818995
user5818995

Reputation:

Check if the parameters passed to a method is one of the constants defined in a class?

I am seeking a way to know if the parameters passed to a method is a constant defined in a specific class. For example:

class MyClass {
    const CONSTANT = 4;
    const ANOTHER_CONSTANT = 5;

    public function aMethod ($a_CONSTANT) {
        // function code
   } 
 } 

$myClass = new MyClass();
$myClass->aMethod(MyClass::CONSTANT); // Fine
$myClass->aMethod(MyClass::ANOTHER_CONSTANT) ; // Still okay
$myClass->aMethod(4); // Not okay
$myClass->aMethod(OtherClass::VALUE); // No way

In the above code, first two calls to aMethod are acceptable but I want the parser to give an error while the third and fourth call to aMethod happens, since the value passed to aMethod is not a constant of a particular class (MyClass, in this case). Is there a syntax to typehint the parameter in aMethod to achieve what I want?

Upvotes: 1

Views: 194

Answers (1)

deceze
deceze

Reputation: 522016

When you pass "a constant", you're not passing the constant itself, you're passing its value. MyClass::CONSTANT and 4 are exactly synonymous. There is no difference between them you could detect. In fact, the compiler replaces all mentions of "MyClass::CONSTANT" with 4 at compile time. That's what constants are.

Upvotes: 1

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