Question

I got a problem

class a
{
     public $aa=1;
     public function dd(){
       $this->aa = 2;
     }
     public function gg(){
       echo   $this->aa ;
     }
}

how come in the go method echo $this->aa still be ‘1’?

Answer 1

Because do is reserved keyword in PHP.

Demo of do as method name. (An error)

Demo without do, successfull outputs 2

You should change method name from do to something else since it is reserved keyword used in do-while loop.