'With' keyword in C++

Look at the following code. It prints 123


#include <iostream.h>

class A
{
public:
A(){a = 123;}
int a;
};
class B
{
public:
A a;
int b;
};
void main()
{
B ttt;
cout << ttt.a.a << endl;
// With ttt.a
// a = 123;
// End With
}

If my previos reply confusesyou, and you want to assign 123 look at the following code




#include <iostream.h>

class A
{
public:
int a;
};
class B
{
public:
A a;
int b;
};
void main()
{
B ttt;
ttt.a.a = 123;
cout << ttt.a.a << endl;
// With ttt.a
// a = 123;
// End With
}

I'm not sure what your post was trying to say but, as stated before, the nearest solution would be below.

Code:

---

//#include <iostream.h> // Not part of the standard!
#include <iostream>

class A
{
public:
        int a;
};

class B
{
public:
        A a;
        int b;       
};
void main()
{
        B ttt;

        // With 'A'.
        A &a = ttt.a;
        a.a = 123;

        cout << a.a << endl;
        cout << ttt.a.a << endl; // Same output.
}

---

Quote:

---

Originally Posted by Zaccheus

Like I said above, C++ does not have properties.

---

Then how do you change button's text, for example? I've never built win apps under C++, but I assumed, it would be the same as in VB, like ButtonName->Text = "123". No?

Quote:

---

Originally Posted by JohnW@Wessex

We made removal of unnecessary this-> part of our coding standards.

---

I'll illustrate the necessity of 'this' with the following code sample:

Code:

---

#include <iostream>
#include <conio.h>
using namespace std;

class A
{
        int a;
public:       
        A() { a = 0; } 
        void SomeFun();       
};
void A::SomeFun()
{
        int a;
        a = 123;
        cout << a << " " << this->a; //those are different 'a'
}
int main()
{
        A ob;
        ob.SomeFun();
        getch(); //to make sure it doesn't close the window
        return 0;
}

---

Quote:

---

Originally Posted by Neolisk

I'll illustrate the necessity of 'this' with the following code sample:

Code:

---

#include <iostream>
#include <conio.h>
using namespace std;

class A
{
        int a;
public:       
        A() { a = 0; } 
        void SomeFun();       
};
void A::SomeFun()
{
        int a;
        a = 123;
        cout << a << " " << this->a; //those are different 'a'
}
int main()
{
        A ob;
        ob.SomeFun();
        getch(); //to make sure it doesn't close the window
        return 0;
}

---

---

All that illustrates is bad naming conventions

Do you always complain about conventions/standards, or just fix the code so that it works as needed with minimum changes made?

Personally I use naming conventions which make it clear whether an object is a data member or a local variable.

Quote:

---

Originally Posted by Neolisk

Then how do you change button's text, for example? I've never built win apps under C++, but I assumed, it would be the same as in VB, like ButtonName->Text = "123". No?

---

No.

When assigning to a property, what actually happens there is that button.Text = "Hello" is internally seen as button.set_Text("Hello"), because reading from a property and writing to a property actually result in function calls.

The way you do it in C++ is by calling a SetText function.

Your C++ example uses public data members, which are something I would avoid in non-trivial classes.

Quote:

---

Originally Posted by Neolisk

I'll illustrate the necessity of 'this' with the following code sample

---

I was talking about unnecessary this->
If it's necessary, then use it!

(Though I don't think any of my code has a this-> in it)