Check if method exists in the same class

Question

So, method_exists() requires an object to see if a method exists. But I want to know if a method exists from within the same class.

I have a method that process some info and can receive an action, that runs a method to further process that info. I want to check if the method exists before calling it. How can I achieve it?

Example:

class Foo{     public function bar($info, $action = null){         //Process Info         $this->$action();     } } 

Answer 1

You can do something like this:

class A{     public function foo(){         echo "foo";     }      public function bar(){         if(method_exists($this, 'foo')){             echo "method exists";         }else{             echo "method does not exist";         }     } }  $obj = new A; $obj->bar(); 

Answer 2

Using method_exists is correct. However if you want to conform to the "Interface Segregation Principle", you will create an interface to perform introspection against, like so:

class A {     public function doA()     {         if ($this instanceof X) {             $this->doX();         }          // statement     } }  interface X {     public function doX(); }  class B extends A implements X {     public function doX()     {         // statement     } }  $a = new A(); $a->doA(); // Does A::doA() only  $b = new B(); $b->doA(); // Does B::doX(), then remainder of A::doA()