Question

I have a working codebase that has a class called Tabs. All methods and variables of this class are defined as static. I understand that a static member of class is shared by all instances of that class’s objects. This class is used to store some type of data into as sets. A lot of different files use the member functions Tabs::find() and Tabs::Insert() without ever instantiating an object of class Tabs. I’m trying to understand how this works and what this programming technique is called. Thanks.

Answer 1

static data members are initialized before main enters, that’s why accessing them works. They reside in static memory, as opposed to dynamic or automatic.

A class with only static members is similar to having global variables and functions, but grouped together. It’s not a programming technique in itself. It’s just globals.

//globals.h
class Globals
{
   static int x;
public:
   static int getX() {return x;}
};

//globals.cpp
#include "Globals.h"
int Globals::x = 1;

//main.cpp
#include "Globals.h"
//x is initialized before call to main
int main()
{
    int x = Globals::getX();
}