Questions tagged [inheritance]
Inheritance is the system in object oriented programming that allows objects to support operations defined by anterior types without having to provide their own definition. It is the major vector for polymorphism in object-oriented programming.
inheritance
42,729
questions
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41
views
Antlr grammars that generate actual class inheritance
Need to know, is it possible to generate parsers, lexers, listeners, etc, by importing subset-grammars? I see that the supergrammar subgrammar pattern is possible, but I'm not sure I see a true class ...
-2
votes
1
answer
58
views
Cast a List<derivedType> into a List<baseType> without breaking the reference
I have multiple lists of type ArmorBase and WeaponBase that inherit the ItemBase class.
I also have a List that represents the current selected item List
public List<ItemBase> ...
-4
votes
2
answers
55
views
I don't want to call the parent constructor. Can we do something about this? [closed]
I am trying to explore JS classes and I am getting error if I am not calling super().
ReferenceError: Must call super constructor in derived class before accessing 'this' or returning from derived ...
1
vote
3
answers
75
views
If I already have an instance of a super class, how can I create an instance of a child class from it?
How do I properly inherit data from an instantiation of a super class? For example, consider something I can get to work, but is confusing in its behaviour:
from dataclasses import dataclass
from ...
- 3,770
0
votes
0
answers
16
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Efficient design solution for handling dynamic marking schemes with multiple levels and subjects
We're developing a grading system for a school with multiple levels (e.g., elementary, middle school, high school) and various subjects within each level (n subjects < 200). The challenge is that:
...
0
votes
1
answer
65
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Calling student method from parent class definition
I'm making an LCD menu and having trouble with the lcdmenu (main menu) and submenu interaction.
class submenu;
class lcdmenu
{
protected:
command **commandlist;
submenu **submenulist;
... ...
-1
votes
1
answer
66
views
Hide fields in child class when inheriting
Is it really impossible to hide these two fields in the inspector of the child class when inheriting, without using a custom inspector?
If yes, then what is the best way to change the value of ...
- 374
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votes
2
answers
41
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Pydantic Inheritance Defaults
How can I typehint a parent BaseModel such that a child subclass can provide defaults for some of the fields:
from pydantic import BaseModel
class Parent(BaseModel):
first: str
second: str
...
- 335
1
vote
1
answer
50
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PHP inheritance with inherited properties
I'd like to have the following class configuration.
class Parent
{
protected ParentMapperInterface $mapper;
public function __construct(ParentMapperInterface $mapper)
{
$this->...
- 524
2
votes
1
answer
34
views
Python Django access fields from inherited model
Hi I have a question related to model inheritance and accessing the fields in a Django template.
My Model:
class Security(models.Model):
name = models.CharField(max_length=100, blank=False)
class ...
- 99
0
votes
1
answer
76
views
Abstract function's copy constructor deleted, class inherited from this class gives error
Given header files named Point.h:
#pragma once
struct Point {
double x, y;
};
and Shape.h:
#pragma once
#include "Point.h"
#include <vector>
class Shape {
public:
...
- 11
0
votes
1
answer
74
views
Strange inheritance behavior with base class
I hope someone can help me since can't quite understand how it is possible that the following code can work.
I have a base class with some classes that derive from it.
Each derived class has its own ...
1
vote
1
answer
49
views
Constructor parameter is null until parent is not initialized
Look at the following code:
abstract class A {
init {
f()
}
abstract fun f()
}
class B(val p: () -> Unit) : A() {
override fun f() {
try {
p()
...
- 3,182
0
votes
1
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44
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Sharing SQLAlchemy models between flask and non-flask python projects
We have 2 projects - Project_A and Project_B. Project_A does data processing, saves processing results to a database, generates an .sql dump and uploads it to cloud storage. Project_B is a flask app, ...
0
votes
2
answers
60
views
Initializing properties of derived classes in Kotlin
I want to know why exactly my code returns "nullnullnull" instead of expected answer and why does it work correctly when method is used.
Consider the following code:
open class Base(
...
