using class C++ example with code and solution

using class C++ programming language  example with code and solution 

1. What will be the output of this code?

class blah {

public:

  static int a; 

  int b;

  blah(int x) {

    b=x;

    a=b+1;

  }

};

int blah::a = 0;

int main(void) {

  blah b1(5);

  blah b2(12);

  cout << "b1.a is " << b1.a << endl;

  cout << "b1.b is " << b1.b << endl;

  cout << "b2.a is " << b2.a << endl;

  cout << "b2.b is " << b2.b << endl;

}

b1.a is 13 b1.b is 12 b2.a is 13 b2.b is 12