Question

Hi Experts can I do dynamic binding like this.
objshapes is the parent class called Shape and Rectangle is the child class. I have a few child classes so depending which shape the user selects, I need to bind the correct shape to the objShapes. So i thought i can bind like this. but i getting an error.

 Shape *objShapes[3];    
 objshapes[size]= &new Rectangle(3,lvaule,5)  

 //error: lvalue required as unary ‘&’ operand

Hope someone can assist. Thanks

IS THIS CORRECT

  objshapes[size]= new Rectangle(3,lvaule,5)  

Answer 1

Shape *objShapes[3];

This declares objshapes as an array of 3 pointers-to-Shape.

objshapes[size]= &new Rectangle(3,lvaule,5)  

This is non-sensical.

IS THIS CORRECT

objshapes[size]= new Rectangle(3,lvaule,5) 

Yes¹, that is correct. new returns a pointer-to-Rectangle, which can be stored in a variable of type pointer-to-Shape. Since objshapes is an array of pointers-to-Shape. objshapes[size] is pointer-to-Shape — which can accept a pointer-to-Rectangle.

^{1. Assuming that size is convertable to an integral type, and has the value 0, 1, or 2.}