Question

I have seen function called from php classes with :: or ->.

eg:

$classinstance::function
or
$classinstance->function

whats the difference?

Answer 1

The :: syntax means that you are calling a static method. Whereas the -> is non-static.

MyClass{

  public function myFun(){  
  }

  public static function myStaticFun(){
  }

}

$obj = new MyClass();

// Notice how the two methods must be called using different syntax
$obj->myFun();
MyClass::myStaticFun();