Thread: Static members in C++

Hi,

I want to do this exercise

Define two classes, each with a static member,
so that the construction of each static member involves a reference to the other.
Where might such constructs appear in real code?
How can these classes be modified to eliminate the order dependence in the constructors?

Is my code correct?

Code:

#include <iostream>
using namespace std;
 
class StepOne
{
     int num;
 public:
     StepOne() 
 { 
  cout << "StepOne's constructor called " << endl;  
 }
};
 
class StepTwo
{
     static StepOne first;
 public:
     StepTwo() 
 { 
  cout << "StepTwo's constructor called " << endl; 
 }
     static StepOne getStepOne() 
 { 
  return (first); 
 }
};
 
StepOne StepTwo::first;
 
int main()
{
     StepTwo st1, st2, st3;
     StepOne first = st1.getStepOne();
 
     return (0);
}

Originally Posted by King Mir

No, you only have one class with a static member, the assignment calls for two.

What about this? Where is the failure here?

Code:

#include <iostream>
using namespace std;
class StepOne
{
 static StepTwo value_st;
        public:
        StepOne()
        {
                cout << "StepOne's constructor called " << endl;
        }
 static StepTwo getStepTwo()
 {
  return (value_st);
 }
};

class StepTwo
{
        static StepOne value_so;
        public:
        StepTwo()
        {
                cout << "StepTwo's constructor called " << endl;
        }
        static StepOne getStepOne()
        {
                return (value_so);
        }
};
StepOne StepTwo::value_so;
StepTwo StepOne::value_st;
int main()
{
        StepTwo st1;
 StepOne st2;
        StepOne value_so = st1.getStepOne();
 StepTwo value_st = st2.getStepTwo();
        return (0);
}

Originally Posted by Joe1903

What about this? Where is the failure here?

Code:

#include <iostream>
using namespace std;
class StepOne
{
 static StepTwo value_st;
        public:
        StepOne()
        {
                cout << "StepOne's constructor called " << endl;
        }
 static StepTwo getStepTwo()
 {
  return (value_st);
 }
};

class StepTwo
{
        static StepOne value_so;
        public:
        StepTwo()
        {
                cout << "StepTwo's constructor called " << endl;
        }
        static StepOne getStepOne()
        {
                return (value_so);
        }
};
StepOne StepTwo::value_so;
StepTwo StepOne::value_st;
int main()
{
        StepTwo st1;
 StepOne st2;
        StepOne value_so = st1.getStepOne();
 StepTwo value_st = st2.getStepTwo();
        return (0);
}

First I had this one,but my collegue said it is not complete.What is missing here to fulfill the assignment?

Code:

#include <iostream>
using namespace std;

struct MemberA
{
        public:
        int x;
        MemberA();
};

struct MemberB
{
        int x;
        public:
        MemberB();
};

class ClassA
{
        public:
        static MemberA x;
};

class ClassB
{
        public:
        static MemberB x;
};

MemberA::MemberA()
{
        x = ClassB::x.x;
        cout << "Aufruf MemberA Konstruktor" << endl;
}

MemberB::MemberB()
{
        x = ClassA::x.x;
        cout << "Aufruf MemberB Konstruktor" << endl;
}

MemberA ClassA::x;
MemberB ClassB::x;
int main()
{
}

Originally Posted by Joe1903

First I had this one,but my collegue said it is not complete.What is missing here to fulfill the assignment?

Code:

#include <iostream>
using namespace std;

struct MemberA
{
        public:
        int x;
        MemberA();
};

struct MemberB
{
        int x;
        public:
        MemberB();
};

class ClassA
{
        public:
        static MemberA x;
};

class ClassB
{
        public:
        static MemberB x;
};

MemberA::MemberA()
{
        x = ClassB::x.x;
        cout << "Aufruf MemberA Konstruktor" << endl;
}

MemberB::MemberB()
{
        x = ClassA::x.x;
        cout << "Aufruf MemberB Konstruktor" << endl;
}

MemberA ClassA::x;
MemberB ClassB::x;
int main()
{
}

Can someone help me please?