pointer objects

[vxk]

I was going through the following code in Bjarne Stroustrups book, when i encountered the following code :

Shape* fct() {

Text tt{Point{200,200},"Annemarie"}
Shape* p =  new Text{Point{100,100}, "Nicholas"};
return p;
}

Can somebody elaborate on line 4. I mean when what kind of code would it be ,where it is useful to use

Shape* p =new Text{….};

instead of

Shape* p =  new Shape; //  

and VICE -VERSA

Thanks!

[keskiverto]

Was there word polymorphism in that chapter?

[Aceix]

Can somebody elaborate on line 4. I mean when what kind of code would it be ,where it is useful to use

Shape* p =new Text{….};

When Text is a class derived from the abstract class Shape, and vice versa for: Text* ptr=new Shape

Aceix.

[vxk]

@Aceix and how would and when would it come to use, to allocate a derived class's
constructor to that of a base class..

[keskiverto]

You don't. Not "constructor in constructor".

You store the address of an object in a pointer.

Derived inverits its base and therefore derived IS-A base and can be used where base is used.

Websearch polymorphism.

[ne555]

> where it is useful to use
> Shape* p =new Text{….};
> instead of
> Shape* p = new Shape;
¿when is it useful to use Shape* p = new Shape;?
http://www.cplusplus.com/forum/general/138037/#msg731921