Class and Structure

[saiavinashiitr]

what is the difference between a class and a structure(struct)...when to use class and when to use struct???

[weaknessforcats]

There is no difference between a class and a struct except one:

The default access to a class member is private whereas the default access to a struct member is public.

Structs are in C++ because they are inherited from the parent language C. A struct is the only way to group member variables under a single name.

A class is an object oriented program concept. A class groups member variables under a single name.

The big secret in C++ is that classes are implemented as structs. No kidding. Create a C++ class using public and private members, add constructors and a destructor, maybe add operator overloads. When it compiles without error, just change the keyword "class" to "struct" and recompile. There will be no errors.

You use class in C++ all the time. You use struct in C (you have no choice). You use struct in C++ to advertise that you really don't understand this object business.

[Sherin]

Class

In OOP, a class is a blueprint from which individual instances are created.
A class is a blueprint for creating objects (a particular data structure), providing initial values for state (member variables or attributes), and implementations of behavior (member functions or methods).
We define a class using the class keyword.
Classes are of reference types.
All the reference types are allocated on heap memory.

Example

#include <stdio.h> 
 
class Test { 
    int x; // x is private 
}; 
int main() 
{ 
Test t; 
t.x = 20; // compiler error because x is private 
getchar(); 
return 0; 
} 

Structure

A struct is similar to a class in terms of definition and instance creation.
We define a struct using the struct keyword.
Structs are of value types.
All the value types are allocated on stack memory.
Classes can contain constructor or destructor.
Structure does not contain parameter less constructor or destructor, but can contain Parameterized constructor or static constructor.

Example

#include <stdio.h> 
 
struct Test { 
    int x; // x is public 
}; 
int main() 
{ 
Test t; 
t.x = 20; // works fine because x is public 
getchar(); 
return 0; 
}