C/C++ Struct vs Class

In C++ the structure and class are basically same. But there are some minor differences. These differences are like below.

• The class members are private by default, but members of structures are public. Let us see these two codes to see the differences.

Example

#include <iostream>
using namespace std;
class my_class {
   int x = 10;
};
int main() {
   my_class my_ob;
   cout << my_ob.x;
}

Output

This program will not be compiled. It will generate compile time error for
the private data member.

Example

#include <iostream>
using namespace std;
struct my_struct {
   int x = 10;
};
int main() {
   my_struct my_ob;
   cout << my_ob.x;
}

Output

10

• When we derive a structure from a class or structure, the default access specifier of that base class is public, but when we deriving a class the default access specifier is private.

Example

#include <iostream>
using namespace std;
class my_base_class {
   public:
   int x = 10;
};
class my_derived_class : my_base_class {
};
int main() {
   my_derived_class d;
   cout << d.x;
}

Output

This program will not be compiled. It will generate compile time error that the variable x of the base class is inaccessible

Example

#include <iostream>
using namespace std;
class my_base_class {
   public:
   int x = 10;
};
struct my_derived_struct : my_base_class {
};
int main() {
   my_derived_struct d;
   cout << d.x;
}

Output

10