Lets say that I have the following C# code: public class Foo { public string someString; public class Bar { public string ReturnSomething() { return someString; } } } I assumed that an inner class could access state from its parent class, but when I try, I get the following error: [CS0120] An object reference… Read More "An object reference is required for the non-static field, method, or property" for nested classes accessing parent class fields

Lets say that I have the following C# code: public class Foo { public string someString; public class Bar { public string ReturnSomething() { return someString; } } } I assumed that an inner class could access state from its parent class, but when I try, I get the following error: [CS0120] An object reference… Read More "An object reference is required for the non-static field, method, or property" for nested classes accessing parent class fields

Considering this example : from dataclasses import dataclass from typing import ClassVar @dataclass class Circle: radius: float pi: ClassVar[float] = 3.14159 circle1 = Circle(5.0) circle2 = Circle(10.0) circle1.pi = 3.14 print(circle1) # gives Circle(radius=5.0) print(circle1.pi) # gives 3.14 I’m very confused because I can’t see the difference between using pi: ClassVar[float] = 3.14159 and pi:… Read More Why using ClassVar's attributes in a dataclass has no effect?

probably a dumb question but I didn’t find an answer, so as far as I learned java does not support inheritance from multiple classes, but every class already inherits from the class Object so how can it inherit from another class?. >Solution : A class only directly inherits from Object if it does not inherit… Read More why classes can inherit from an another class if they already inherit from Object?

I’ve been following Python tutorials on YouTube for the past couple of days now, and have made it to an OOP section. The example code has two modules, client.py and car.py. Within car.py is a class called Car, with attributes for the make, model, color (all strings), and year (integer). I decided to expand on… Read More How can I write the output of a class method to a file in Python?

I am a Python beginner grinding through Python Crash Course by Eric Matthes. I am currently on chapter 9 Classes and Object Oriented Programming. I have the following code: class User: # Define the class """A simple attempt to model website users.""" def __init__(self, first_name, last_name, age, username, city, country): self.first_name = first_name.title() self.last_name =… Read More Python Classes: Differences Between Explicitly Writing Attributes Inside __init__() Parentheses

In such a case, how to access the property in the first class from the second class? class First { public $var = ‘First Non-Static Property’; public function __construct() { echo $this->var; } } class Second extends First { public $var = ‘Second Non-Static Property’; public function __construct() { parent::$var; } } $object = new… Read More How to get non-static variable from inherited class?

I am new to Vector while solving Twosum problem from leetcode, encountered following Compilation error : Line 4: Char 26: error: no viable conversion from ‘std::vector<int, std::allocator<int>>::iterator’ (aka ‘__normal_iterator<int *, std::vector<int, std::allocator<int>>>’) to ‘unsigned int’ for(unsigned int i=nums.begin();i<nums.end();i++) Here is my code: class Solution { public: vector<int> twoSum(vector<int>& nums, int target) { for(unsigned int i=nums.begin();i<nums.end();i++)… Read More How to fix " no viable conversion from 'std::vector<int, std::allocator<int>>::iterator' to 'unsigned int' "?

More precisely, I would like to remove the line self.B = B in the code below. class A: def __init__(self, x): class B: def __init__(self): self.x = x self.B = B >Solution : From what I understand, you want to create a class in A.__init__ which is directly stored into an instance variable, without first… Read More In Python, I have a class as an attribute of an object. Can I simplify this code?

I am trying to instantiate an object using data from an Excel document . For some reason I’m getting this exception: Microsoft.CSharp.RuntimeBinder.RuntimeBinderException: ‘The best overloaded method match for ‘TRY.Employee.Employee(double, string, string, double)’ has some invalid arguments’ becouse of this line: employees.Add(new Employee(ws.Cells[i + 1, 1].Value, ws.Cells[i + 1, 2].Value, ws.Cells[i + 1, 3].Value, ws.Cells[i +… Read More when instantiating an object using a constructor, an exception is thrown in c#: Microsoft.CSharp.RuntimeBinder.RuntimeBinderException