What do you mean by static variable and static function give suitable example?

Answer 1

If this is a homework assignment, you really should try to answer it on your own first, otherwise the value of the reinforcement of the lesson due to actually doing the assignment will be lost on you.

A static variable outside of a class is a variable whose value persists for the duration of the program's run time. Even if the variable goes out of scope, when it goes back into scope its value will be the last value that was assigned to it.

A static variable inside a class is a variable that is part of the entire class definition. There is only one copy of that variable, and it is shared by all instances of the class.

A static function is a method of a class that can only access static variables. It cannot access instance variables because it has no this pointer associated with its invocation. It is useful because you do not need an instance of the class to invoke it, so you can use it to iniitialize static class variables.

// using ellipses (...) to indicate tabs for clarity

class myclass {
... static c_Instances;
... static initClass () {
... ... c_Instances = 0;
... }
... myclass () { // constructor
... ... c_Instances++;
... ... // other stuff
... }
... ~myclass () { // destructor
... ... c_Instances--;
... ... // other stuff
... }
... // other stuff
}

// out of class invocation
myclass::initClass ();