constructor3.cpp

#include <iostream>

class Bar {
public:
  int i;
  /* constructor with an agrument to init i to */
  Bar(int new_i) : i(new_i) {
  }
};

class Foo {
public:
  int data; 
  Bar bar;
  /* default constructor: init data to zero */
  Foo(): bar(3), data(0) {
  }
};

using namespace std;

int main() {
  Foo obj1; // default constructor
  cout << obj1.data << endl;
  cout << obj1.bar.i << endl;
  return 0;
}

/* output
0
3
*/