Difference Between Structure and Class in C++

In C++, a structure works the same way as a class, except for the difference that members of a class are private by default and members of a structure are public by default. 

For example, program 1 fails in compilation but program 2 works fine, 

Program 1

// C++ Program to demonstrate that // Members of a class are private // by default #include <iostream> using namespace std; class Test {  // x is private  int x; }; int main() {  Test t;    // compiler error because x  // is private  t.x = 20;  return t.x; } 

 Output:

./cf03c8d1-d4a3-43ea-a058-fe5b5303167b.cpp: In function 'int main()': ./cf03c8d1-d4a3-43ea-a058-fe5b5303167b.cpp:10:9: error: 'int Test::x' is private int x; ^ ./cf03c8d1-d4a3-43ea-a058-fe5b5303167b.cpp:18:7: error: within this context t.x = 20; ^ ./cf03c8d1-d4a3-43ea-a058-fe5b5303167b.cpp:10:9: error: 'int Test::x' is private int x; ^ ./cf03c8d1-d4a3-43ea-a058-fe5b5303167b.cpp:20:14: error: within this context return t.x; ^

Program 2:

// C++ Program to demonstrate that // members of a structure are public // by default #include <iostream> using namespace std; struct Test {  // x is public  int x; }; int main() {  Test t;  t.x = 20;  // works fine because x is public  cout << t.x; } 

20

There is no other difference as structures support all features of a class like member methods, inheritance and virtual functions. The following is a summary of differences

To know about the Difference between C structures and C++ structures refer to this article.