Local classes in C++

Local class is a class defined inside a function. Following are some of the rules for using these classes.

• Global variables declared above the function can be used with the scope operator "::".
• Static variables declared inside the function can also be used.
• Automatic local variables cannot be used.
• It cannot have static data member objects.
• Member functions must be defined inside the local classes.
• Enclosing functions cannot access the private member objects of a local class.

Example :

#include <iostream.h> int y; void g(); int main() { g(); return 0; } void g() { class local { public: void put( int n) {::y=n;} int get() {return ::y;} }ab; ab.put(20); cout << "The value assigned to y is::"<< ab.get(); }

Result :
In the above example, the local class "local" uses the variable "y" which is declared globally. Inside the function it is used using the "::" operator. The object "ab" is used to set, get the assigned values in the local class.