How to create derived class in c++ -

i'm confused on how deal inheritance in c++

i'd pass parameters on constructor. got run when create class without parameters.

this small program:

#include <iostream> using namespace std;  // base class  class shape {    protected:    int width, height;    public:    shape(int w, int h) {       width = w;     height = h;   }    void setdimensions(int w, int h)  {     width = w;     height = h;   }  };  // new class rectangle based on shape class  class rectangle: public shape {   public:      int getarea() {       return (width * height);     }  }; 

when compile errors:

$ g++ inheritance.cpp -o inheritance -g -std=c++11 inheritance.cpp:44:13: error: no matching constructor initialization of 'rectangle'   rectangle r(3, 4)             ^ ~~~~ inheritance.cpp:33:7: note: candidate constructor (the implicit copy constructor) not viable: requires 1 argument, 2 provided class rectangle: public shape {       ^ inheritance.cpp:33:7: note: candidate constructor (the implicit move constructor) not viable: requires 1 argument, 2 provided inheritance.cpp:33:7: note: candidate constructor (the implicit default constructor) not viable: requires 0 arguments, 2 provided 

constructors aren't inherited shape. you'll need provide constructor rectangle, can take parameter signature:

rectangle(int w, int h) : shape(w,h) { }