Why can other methods be “static” but a constructor cannot?

Question

I do not understand why the main method has to be static. I understand static variables but static methods are difficult for me to grasp. Do static method exists so that one

Answer 1

Static methods belong to a class, not an object. The main method must be static because it is called first, before any other code has executed to instantiate any objects. It provides an entry point to the program. Static methods are called from outside of the container of an object. The same is true of static class variables. Only one copy exists for the entire class, as opposed to a member variable, which is created once for each object created from a class. They are used to store data for the class, such as the number of object instances have been created and not destroyed. This data belongs with the class. A good example of a static method is in the singleton pattern, where the constructor is private and can only be accessed by a static member function. A function outside the class would be unable to replicate this functionality. This method acts on class data and objects, so logically belongs to the same class. This all boils down to encapsulation. A class is responsible only for itself and knows only itself.

On the other hand, object methods are meant to operate on the data associated with a single instance of a class, an object. Constructors are the code that is used to initialize an object and set it's data to an initial state. They are executed immediately (and automatically) after the memory has been allocated to store a new object. Even if you do not explicitly define a constructor, a kind of "default constructor" is executed in order to map the object's member variables and the object's method code to the new object.

Hope this helps.