class-variables

I need to make a bunch of class variables and I would like to do it by looping through a list like that: vars=('tx','ty','tz') #plus plenty more class Foo(): for v in vars: setattr(no_idea_what_should_go_here,v,0) is it possible? I don't want to make them for an instance (using self in the __init__) but as class variables. You can run the insertion code immediately after a class is created: class Foo(): ... vars=('tx', 'ty', 'tz') # plus plenty more for v in vars: setattr(Foo, v, 0) Also, you can dynamically store the variable while the class is being created: class Bar: locals()['tx'] =

Let's say I have a class like this (and also further assume that all the private variables: public class Item { private String _id = null; private String _name = null; private String _description = null; ... } Now, if I want to build a toString() representation of this class, I would do something like this inside the Item class: @Override public String toString() { return (_id + " " + _name + " " + _description); } But what if I have say 15 private variables inside the class? Do I have to write the name of each and every variable like this? Ideally, I would like to get over with the task by

First, a puzzle: What does the following code print? public class RecursiveStatic { public static void main(String[] args) { System.out.println(scale(5)); } private static final long X = scale(10); private static long scale(long value) { return X * value; } } Answer: 0 Spoilers below. If you print X in scale(long) and redefine X = scale(10) + 3 , the prints will be X = 0 then X = 3 . This means that X is temporarily set to 0 and later set to 3 . This is a violation of final ! The static modifier, in combination with the final modifier, is also used to define constants. The final modifier

I tried the following code in codepad.org: class test { const TEST = 'testing 123'; function test () { $testing = 'TEST'; echo self::$testing; } } $class = new test; And it returned with: 1 2 Fatal error: Access to undeclared static property: test::$testing on line 6 I want to know whether referencing a class constant with a variable would work on my server at home which runs php 5.2.9 whereas codepad uses 5.2.5 . What are changes in class variables with each version of PHP? The Scope Resolution Operator (also called Paamayim Nekudotayim) or in simpler terms, the double colon, is a token that

Python 3.4.0a1 Windows 8.1 Class Created: class Bank(object): bankrupt = False Command entered in IDLE __main__ with the following results: >>> a = Bank() >>> b = Bank() >>> a.bankrupt False >>> b.bankrupt False >>> b.bankrupt = True >>> b.bankrupt True >>> a.bankrupt False Expected output: I expected a.bankrupt to change to True when I changed b.bankrupt since the variable bankrupt is defined for the entire class and not for a single instance (with self.bankrupt ) Why is this not happening? You assigned to a new attribute to the instance instead. To change a class attribute, assign directly

I am having a hard time understanding instance variable, class variable and the difference between them in ruby... can someone explain them to me? I have done tons of Google searches, just can't understand them fully. Thank you! Let's say you define a class. A class can have zero or more instances. class Post end p1 = Post.new p2 = Post.new Instance variables are scoped within a specific instance. It means if you have an instance variable title , each post will have its own title. class Post def initialize(title) @title = title end def title @title end end p1 = Post.new("First post") p2 = Post

How would you I came up with this interesting (at least to me) example. import numpy as np class Something(object): a = np.random.randint(low=0, high=10) def do(self): self.a += 1 print(self.a) if __name__ == '__main__': something = Something() print(something.__str__()) something.do() something2 = Something() print(something2.__str__()) something2.do() something3 = Something() print(something3.__str__()) something3.do() The above prints the following in the console: $ python test.py <__main__.Something object at 0x7f03a80e0518> 1 <__main__.Something object at 0x7f03a80cfcc0> 1 <__main__