how to use static class variable in c++ code example
Example 1: static inside local scope in c++
#include
//Singleton class is a class having only one instance
class SingleTon {
public:
static SingleTon& Get() {
static SingleTon s_Instance;
return s_Instance;
}//there is only one instance of static functions and variables across all instances of class
void Hellow() {}
};
void Increment() {
int i = 0;//The life time of variable is limited to the function scope
i++;
std::cout << i << std::endl;
};//This will increment i to one and when it will reach the end bracket the lifetime of var will get destroyed
void IncrementStaticVar() {
static int i = 0;//The life time of this var is = to program
i++;
std::cout << i << std::endl;
}//This will increment i till the program ends
int main() {
Increment();//output 1
Increment();//output 1
Increment();//output 1
IncrementStaticVar();// output 2
IncrementStaticVar();// output 3
IncrementStaticVar();// output 4
IncrementStaticVar();// output 5
SingleTon::Get();
std::cin.get();
}
Example 2: static in class c++
#include
class Entity {
public:
static int x,y;
static void Print() {
std::cout << x << ", " << y << std::endl;
}// sta1tic methods can't access class non-static members
};
int Entity:: x;
int Entity:: y;// variable x and y are just in a name space and we declared them here
int main() {
Entity e;
Entity e1;
e.x = 5;
e.y = 6;
e1.x = 10;
e1.y = 10;
e.Print();//output => 10 because variable x and y being static point to same block of memory
e1.Print();//output => 10 because variable x and y being static point to same block of memory
Entity::x; //you can also acess static variables and functions like this without creating an instance
Entity::Print(); //you can also acess static variables and functions like this without creating an instance
std::cin.get();
}