FUNCTION returns the name of the current function or method, not the class name; 2. When METHOD is used in a method, it returns the format of "class name:: method name", containing the context information of the class; 3. The two behave the same in independent functions; 4. When debugging object-oriented code, it is recommended to use METHOD to obtain more complete call information; 5. If you need complete namespace information, you need to combine get_class($this) or reflection mechanism. Therefore, the choice depends on the level of detail of the desired context.

You've probably seen both __FUNCTION__ and __METHOD__ in PHP debugging or logging code and wondered: Are they really that different? The answer is yes — subtly, but importantly so. Let's break down what each one does and when to use which.

What __FUNCTION__ Gives You

__FUNCTION__ is a magic constant that returns the name of the current function as a string. It works inside both standalone functions and class methods.

 function greet() {
    echo __FUNCTION__;
}

greet(); // Output: greet

Inside a class method, it only returns the method name — not the class:

 class Person {
    public function saysHello() {
        echo __FUNCTION__;
    }
}

$person = new Person();
$person->sayHello(); // Output: sayHello

So regardless of context, __FUNCTION__ gives you just the bare function (or method) name.

What __METHOD__ Includes

__METHOD__ also returns the current function name — but with a key difference: it includes the class name when used in a method .

 class Person {
    public function saysHello() {
        echo __METHOD__;
    }
}

$person = new Person();
$person->sayHello(); // Output: Person::sayHello

Notice the Class::method format. This makes __METHOD__ especially useful for debugging in object-oriented code, where knowing which class the method belongs to matters.

Even in inherited or overridden methods, __METHOD__ referers to the method where it's actually written — not the caller. That's important.

For standalone functions, __METHOD__ behaves just like __FUNCTION__ :

 function standalone() {
    echo __METHOD__;
}

standalone(); // Output: standalone

Key Differences at a Glance

When to Use Which?

• Use __FUNCTION__ when:

  • You're in procedural code.
  • You only need the function name.
  • You want consistency, minimum output.

• Use __METHOD__ when:

  • You're debugging class methods.
  • You need context about which class a method is in.
  • You're logging in a large codebase with many similarly named methods across classes.

For example, in a logging utility inside a method:

 error_log("Entering " . __METHOD__);
// Output: Entering UserValidator::validateEmail

That's much more informative than just validateEmail .

One small gotcha: __METHOD__ includes the class name exactly as declared — so if you're using namespaces, it won't include the full namespace unless you manually add it. If you need full resolution, you'll need get_class($this) or reflection.

So while both constants seem similar, the choice depends on how much context you need. For quick debugging in classes, __METHOD__ wins. For lightweight, universal function naming, __FUNCTION__ is cleaner.

Basically: same neighborhood, different addresses.

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