static-variables

Let's say I have this program: class Foo { public: unsigned int bar () { static unsigned int counter = 0; return counter++; } }; int main () { Foo a; Foo b; } (Of course this example makes no sense since I'd obviously declare "counter" as a private attribute, but it's just to illustrate the problem). I'd like to know how C++ behaves in this kind of situation: will the variable "counter" in the bar() method be the same for every instance? Yes, counter will be shared across all instances of objects of type Foo in your executable. As long as you're in a singlethreaded environment, it'll work as

I have some task to solve and the most important part at the moment is to make the script as time-efficient as possible. One of the elements I am trying to optimize is memoization within one of the functions. So my question is: Which of the following 3-4 methods is the most efficient / fastest method of implementing memoization in Python? I have provided code only as an example - if one of the methods is more efficient, but not in the case I mentioned, please share what you know. Solution 1 - using mutable variable from outer scope This solution is often shown as the example memoization, but I

I want to have the following setup: abstract class Parent { public static String ACONSTANT; // I'd use abstract here if it was allowed // Other stuff follows } class Child extends Parent { public static String ACONSTANT = "some value"; // etc } Is this possible in java? How? I'd rather not use instance variables/methods if I can avoid it. Thanks! EDIT: The constant is the name of a database table. Each child object is a mini ORM. you can't do it exactly as you want. Perhaps an acceptable compromise would be: abstract class Parent { public abstract String getACONSTANT(); } class Child extends

I've been running into this problem many times and I never bothered to learn why its happening and learn what "static" actually means. I just applied the change that Eclipse suggested and moved on. public class Member { // Global Variables int iNumVertices; int iNumEdges; public static void main(String[] args) { // do stuff iNumVertices = 0; // Cannot make a static reference to the non-static field iNumVertices // do more stuff } // main end } So eclipse tells me to do static int iNumVertices; and I'm not sure why. So what exactly is "static", how is it used, what is the purpose of using

I want to access a static variable from a static method: #!/usr/bin/env python class Messenger: name = "world" @staticmethod def get_msg(grrrr): return "hello " + grrrr.name print Messenger.get_msg(Messenger) How to do it without passing grrrr to a method? Is this the true OOP?.. Anything like name or self.name seems not working: NameError: global name 'name' is not defined and NameError: global name 'self' is not defined Dmitry Isaev Use @classmethod instead of @staticmethod . Found it just after writing the question. In many languages (C++, Java etc.) "static" and "class" methods are

I have someting like this class A: __a = 0 def __init__(self): A.__a = A.__a + 1 def a(self): return A.__a class B(A): def __init__(self): # how can I access / modify A.__a here? A.__a = A.__a + 1 # does not work def a(self): return A.__a Can I access the __a class variable in B ? It's possible writing a instead of __a , is this the only way? (I guess the answer might be rather short: yes :) So, __a isn't a static variable, it's a class variable. And because of the double leading underscore, it's a name mangled variable. That is, to make it pseudo-private, it's been automagically renamed to _