Tips C++
=========================


Using Classes and Objects Method 1
------------------------------------------

.. code-block:: c++

  #include <iostream>
  using namespace std;

  class Class2{
  public:
      Class2(int arg1, int arg2)
      :x{arg1+1},y{arg2}{
          cout << "This is from Class2 constructor\n";
      }

      void meth(){
          cout << "Calling **meth** from Class2\n";
          cout << "x+1=" << x << ", y=" << y;
      }
  private:
      int x,y;
  };

  class Class1{
  private:
      // how to use **Class2** as a member of **Class1** ?
      Class2 class2AsClass1Member;
  public:
      Class1(int arg1, int arg2)
      :class2AsClass1Member{Class2(arg1,arg2)}{

      }

      void method1(){
          // how to use **meth** of **Class2** in **method1** ?
          class2AsClass1Member.meth();
      }

      void method2(){
          // how to call **method1** inside **method2** ?
          method1();
      }
  };

  int main(){
      Class1 c1(1,2);
      c1.method2();
      return 0;
  }  

Using Classes and Objects Method 2
------------------------------------------

.. code-block:: c++
  
  #include <iostream>

  //////// Begin Class1 //////////////
  class Class1{
  public:
      Class1(int m);
      int add(int n);

  private:
      int mValue;
  };

  Class1::Class1(int m) {
      mValue = m;
  }

  int Class1::add(int n) {
      return mValue + n;
  }
  //////// End Class1 //////////////

  //////// Begin Class2 //////////////
  class Class2{
  public:
      Class2(int n);
      int plus1(int a);
      int plus2();

  private:
      Class1 *c1;
  };

  Class2::Class2(int n) {
      c1 = new Class1(n);
  }

  int Class2::plus1(int a) {
      return a+1;
  }

  int Class2::plus2() {
      // First **+1** using **Class1.add()**
      // Then **+1** using **Class2.plus1()**
      return plus1(c1->add(1));
  }
  //////// End Class2 //////////////

  int main(){
      Class2 c2(3);
      std::cout << c2.plus2();
      return 0;
  }