Upcasting permits an object of a subclass type to be treated as an object of any superclass type.
Questions tagged [upcasting]
244 questions
0
votes
1 answer
C++ A polymorphic class, virtual function and casting for performance
I have the following classes:
class State
{
protected:
Vec3D accel;
Vec3D gyro;
Vec3D gps;
float reward;
public:
boost::ptr_vector actions;
...
virtual bool isTerm();
}
class guState : public State
{
…
Ælex
- 14,432
- 20
- 88
- 129
0
votes
2 answers
Changing one row in 2D ArrayList in java changes all the rows
I want to book one seat in a cinema hall according to input but when I am trying to do that it changes all the rows.
Booked seat is denoted by 'B'.
Method that changes the state of cinema hall:
public void bookSeat(int row, int seat) {
…
Piyush Keshari
- 170
- 2
- 10
0
votes
1 answer
upcasting to interface with private inheritance
I have the following situation
class Interface {
};
class ComplicatedObject : public Interface {
};
and I would like to give a simplified version of the ComplicatedObject, still providing the Interface. I was thinking to private inheritance, such…
Teloze
- 279
- 2
- 8
0
votes
0 answers
Explicit up casting & Implicit up casting
I'm trying to find the difference between Explicit up casting and Implicit up casting but there's not so much posts about them. Somebody help me pls?
0
votes
1 answer
How to upcast an static std::optional
class Child: public Base {.....}
class Child
{
static std::optional; \\Does not work. Please help
return instance;
}
}
I'm…
rstr1112
- 308
- 4
- 13
0
votes
0 answers
C++ AST Design, best way to modify upcasted Node members to change children
I need some advice on my AST design. I'm using a pretty typical AST node system for a simple interpreter.
At this point I'm trying to implement simple constant propagation. This involves transformations of the node tree which has led to some…
Tom
- 1,235
- 9
- 22
0
votes
1 answer
Is an object accessible from a previous reference after it has been upcast (in Java)?
Say A is a parent class. Let B and C be its child classes.
A a;
B b = new B(args);
a = b;
Is the type B object still accessible via b, or has it been permanently upcast to type A?
user11991978
0
votes
2 answers
When upcasting an object, what parts refer to the parent and what parts refer to the child?
In the example below, I am confused as to why upcasting seems to refer to some parts of the parent class and some parts of the actual class.
public class B extends A{
int fi = 15;
public static void main(String[] args){
B b = new B();
…
Reno Gonda
- 3
- 1
0
votes
1 answer
c# How to put all dictionary into an object of derived type from Dictionary?
class XDictionary : Dictionary
{
}
Dictionary d = new Dictionary
{
{ "x", "xx" },
{ "y", "yy" },
{ "z", "zz" }
};
…
0
votes
1 answer
A trick to enable casting over non-public inheritances
This is a followup related to my previous question where I investigated the problem and found that up- and downcasting seem to be working correctly over public inheritance relations. For example, this code does not even compile:
class A {
};
class…
peterh
- 11,875
- 18
- 85
- 108
0
votes
0 answers
How is this casting happening in the following java code
I do not understand how the casting is done on var2
The following line does not Compile as methodA1() not present in interface reference I1
String var = i1.methodA1();
Hence I1 requires a cast to invoke methodA1
I do not understand how the casting…
Anshul Gupta
- 265
- 2
- 12
0
votes
1 answer
Upcasting; why do i get the output 11
So i ran this code and I don't understand why I got the output 11:
class Parent{
protected int counter;
public Parent(){counter++;}
}
class Child extends Parent{
public Child(){
System.out.print(counter);}
}
}
public class Test{
…
silvermaze
- 133
- 1
- 1
- 3
0
votes
1 answer
Java Casting To Parent Type and ignore child type attributes
I am trying to cast a child type to a parent type. The thing is since the child class extends parent class, when casting to the parent type child specific attributes are also kept. I would like to leave out some of the child class attributes and…
Nesan Mano
- 1,892
- 2
- 26
- 43
0
votes
1 answer
Why is automatic upcasting from unique_ptr to unique_ptr
ControllerSender is the base class, and several classes will be direct children of that (only BasicSender is in this example) and instantiated through a factory function MidiControllers::AddSender.
A pointer to the instantiated object, along with…
rsjaffe
- 5,600
- 7
- 27
- 39
0
votes
3 answers
Upcasting/Downcasting in Java
I am trying to understand upcasting and downcasting in Java and I am confused by the following scenario (about my code, which is below):
First - why is it that the code does not compile when I include the line myAnimal.bark();,
and Second -…
coolcow
- 45
- 6