Class TestClass {
public:
        // localVariable exists only inside doThings() - once doThings() finishes, localVariable will be destroyed.,
    inline void doThings(int localVariable = 10)
    {
        // Because classVariable is a member of TestClass, it exists as long as the instance of the class does
        classVariable = localVariable;

    }

    int classVariable = 5;

};


int main ()
{

    TestClass dongs = new TestClass();

    // Prints "5", because when we create the class, classVariable defaults to 5
    printf("%d", dongs.classVariable);

    dongs.doThings(2020);
    // Prints "2020", because we gave the value 2020 to doThings, and it created localVariable with value of 2020, and then copied that value in to classVariable
    printf("%d", dongs.classVariable);

    dongs.doThings();
    // Prints 10, because the default value of localVariable is 10. We didn't give it a value, so it uses default.
    printf("%d", dongs.classVariable);


    /*
    * No where inside main can we ever say: dongs.localVariable - it doesn't exist in the class, it only exists *inside* the function doThings.
    * We can never go TestClass.classVariable or TestClass::classVariable, because TestClass is the name of the class.
    * To access any function or variable, we need to create an instance of the class (first line of main()). UNLESS, the function or variable is static - then it persists even if we don't create an instance of the class
    */


}