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Questions tagged [class-instance-variables]

in ruby, where classes are objects, this means the instance variables of the class object itself

Here is an example:

class Test
  @ins1 = "gah"

  def initialize()
    @ins2 = "wtf?"
  end
end

@ins2 is an instance variable and @ins1 is a class instance variable. This might hopefully shed some more light over it: ruby: class instance variables vs instance variables

73 questions
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Problem with class instances, Android

I am trying to make a game for android I have a bitmap and canvas instance in my main class. I have another instance of, lets say, renderer class. That renderer class is in the same package, but not the subclass of my main class. If i pass the…
Eric Cartman
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Can't figure out how to create a "list" instance variable using class in Python

This is my code: class Category(): def __init__(self,category,balance=0,ledger=[]): self.category = category self.balance = balance self.ledger = ledger def check_funds(self,amt): if amt >…
Emeric FOKOUONG TOUOLAC
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Java how to call method in another class

Sorry for the basic question but I'm learning, new to programming. I am trying to call a method that is in another class but I'm unable to without passing in the required values for the constructor of Cypher class. Do i really need a new instance of…
Charlotte O'Regan
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Class Variables

Explain please, I can not understand. class Foo @a = 123 @@b = 123 end What are the advantages of variable objects-classes and the class variables? When should I use first, and in which the second?
user413881
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@coffee_hour = Plan.find_by_event(:coffee_hour) ...Is it possible to link using a variable like this?

My Links table has five different events and I use partials because they are scattered around the page. As an examples, "coffee_hour", and "wine_time." Each event has a url and a time. In my controller I have: @coffee = Link.find_by(event:…
Tom Connolly
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Create a new instance of parent's class variable for each child class

I have this parent class: class ListBase @@list = [] def self.list @@list end end I'm trying to create two child classes like so: class Child1 < ListBase end class Child2 < ListBase end I was under the impression that each of these…
Ashish Acharya
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Django Field Instances overriding each others arguments

I am testing and preparing a new Django package for using bleach with Text and Char fields in the Django ORM and with DRF. I've hit a bit of a roadblock with it however and it has made me take pause and wonder if I truly understand how a models…
Routhinator
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Hierarchical abstraction in c++

I have following abstraction in my code: class A{}; class B: public A{}; class C: public B{}; Now when I declare an instance of class C every thing is OK. The problem is when I declare class C in a function (with new) an return it as a pointer. I…
Kawsar Haghshenas
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how classes can inherit tk.frames when being called as a module in python

I am a tk newbie and am having trouble importing classes and having them inherit frames. If I stack all the code in one file it works. Something like (I found this on Github sorry for no attribution), imports... class Clock(Frame): def…
superhero
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Why are statically bound methods not involved in the CIR ( Class instance Record ) of the class while dynamically bound methods are?

I read in Sebesta that static bound methods do not need to be stored in the CIR but i cant figure out why. If it is not stored in the CIR, how does the compiler know which statically bound method is being referred to and where it is stored?
Gagan Ganapathy
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instance_variable_set is not setting the right variable in an instance

I have an API endpoint I'm testing using Ruby. I have 8 tests that look like the following: it "must rate limit on this api" do body = { .. } # Current limits assigned to this api endpoint are 5 requests every 5 minutes. # So this test…
theGreenCabbage
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Choosing a controller for a layout class instance variable in Rails

I have a DateTime class instance variable @current_year = DateTime.now.year, which I have set into a footer partial. This partial is rendered across several of my clientside pages (and across multiple controllers as <%= render 'layouts/page_footer'…
Boucherie
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Can python class variable be used as both class and instance variable?

I am very confused after working with Django Framework and the model of Djano Framework class User(models.Model): first_name = models.CharField(max_length=20) last_name = models.CharField(max_length=20) email_address =…
Mr. Suryaa Jha
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Python: Can't search through list of class instance variables

I'm trying to create a chemistry GUI that shows various information about each element. I'm using a list of class instances to print out the information, but I continue to get a 'list' object has no attribute 'atomic_number'. This is the class I…
user7454726
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Ruby: Nested Array behaving strangley as an Instance Variable

For our assignment, we were meant to create tic-tac-toe on a board of any size and accept an array as the input. I still am not fully grasping the attr_accessor module, and I'm pretty sure I used it incorrectly. class Board attr_accessor :grid …
Sean Chowdhury
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