Constructor Overloading in C

0 votes

My C++ overloading does not act as I assume it should:

#include "Node.h"
#include <iostream>

Node::Node()
{
    cout << "1" << endl;
    Node(Game(), 0.0);
}

Node::Node(double v)
{
    cout << "2" << endl;
    Node(Game(),v);
}

Node::Node(Game g, double v)
{
    cout << "3" << endl;
    numVisits = 0;
    value = v;
    game = g;
}

And the output from:

Node n(16);
cout << n.value << endl;

is 0, when it should be 16.

What am I doing incorrectly?

Jun 6, 2022 in C++ by Nicholas
• 7,760 points
405 views

1 answer to this question.

0 votes

In your function Object() { [native code] }, Node(Game(),v); does not work as expected. 

It simply creates a temporary without actually using it, and has no effect. 

When control passes over the ;, it immediately destroys the temporary.

Initializing the members in each function Object() { [native code] } is the correct way to go. 

You could put their shared code in a private init() member function and call it from each function Object() { [native code] }, as shown below:

class Foo {
    public:
        Foo(char x);
        Foo(char x, int y);
        ...
    private:
        void init(char x, int y);
};

Foo::Foo(char x)
{
    init(x, int(x) + 3);
    ...
}

Foo::Foo(char x, int y)
{
    init(x, y);
    ...
}

void Foo::init(char x, int y)
{
    ...
} 

Most compilers do not yet support C++11's delegation feature, which allows constructors to call other peer constructors

answered Jun 21, 2022 by Damon
• 4,960 points

Related Questions In C++

0 votes
0 answers

Constructor Overloading in C++

My C++ overloading does not work as I expect it to: #include "Node.h" #include <iostream> Node::Node() { cout ...READ MORE

Jun 2, 2022 in C++ by Nicholas
• 7,760 points
406 views
0 votes
1 answer

What is the difference between operator overloading and operator overriding in C++?

Some people use the latter word to ...READ MORE

answered Aug 2, 2022 in C++ by Damon
• 4,960 points
1,947 views
0 votes
1 answer

Declare abstract class in c++

An abstract class is one that is intended to be used as a base class .  At least one pure virtual function exists in an abstract class.  A pure virtual function is declared in the class declaration by using a pure specifier (= 0) in the declaration of a virtual member function. Here is an example of an abstract class: class AB { public: virtual void f() ...READ MORE

answered May 31, 2022 in C++ by Damon
• 4,960 points
573 views
0 votes
1 answer

What data structure is inside std::map in C++?

An associative container is std::map. The standard's ...READ MORE

answered May 31, 2022 in C++ by Damon
• 4,960 points
854 views
0 votes
1 answer

setuptools: build shared libary from C++ code, then build Cython wrapper linked to shared libary

There is a seemingly undocumented feature of setup that ...READ MORE

answered Sep 11, 2018 in Python by Priyaj
• 58,020 points
701 views
0 votes
1 answer

setuptools: build shared libary from C++ code, then build Cython wrapper linked to shared libary

There is a seemingly undocumented feature of setup that ...READ MORE

answered Sep 21, 2018 in Python by Priyaj
• 58,020 points
2,422 views
0 votes
1 answer

How to pass large records to map/reduce tasks?

Hadoop is not designed for records about ...READ MORE

answered Sep 25, 2018 in Big Data Hadoop by Frankie
• 9,830 points
1,461 views
0 votes
1 answer

Invalid method parameters for eth_sendTransaction

params needs to be an array, try {"jsonrpc":"2.0","method":"eth_se ...READ MORE

answered Sep 28, 2018 in Blockchain by digger
• 26,740 points
1,879 views
0 votes
1 answer

C++ - Overloading vs Overriding in Inheritance

In C++, a derived class's method only overrides the base class's method if their declarations match (I say "match," but I'm not sure what the formal term is).  That is, all arguments must be of the same type, with the same const qualification.  If there are any mismatches, the derived class's method hides all methods with the same name rather than overriding.  This is what the "ERROR" in your image is attempting to convey.  So, in that image, / overrides in a comment is incorrect and misleading. Yes, many C++ instructors are unaware of these somewhat esoteric details. Furthermore, if you want to override, your base class's method must be virtual; otherwise, polymorphism will not work. . We could also say that the derived-class method hides the base-class method if it wasn't virtual.  The part about hiding, on the other hand, has almost no meaning here; what this term really means is that you're not in charge. Furthermore, overloading is the presence of multiple methods with the same name but different signatures, as you may have noticed. To be useful, they must all be present in the derived class; otherwise, they will be hidden if the derived class only has one method, fa1, and the other fa1 are in the base. There is, however, a syntax sugar that "copies" all fa1 from base to derived, removing all the hidden semantics: class A { public: void fa1(); ...READ MORE

answered Jun 7, 2022 in C++ by Damon
• 4,960 points
834 views
0 votes
1 answer

C++ - Overloading vs Overriding in Inheritance

In C++, a derived class's method only overrides the base class's method if their declarations match (I say "match," but I'm not sure what the formal term is).  That is, all arguments must be of the same type, with the same const qualification.  If there are any mismatches, the derived class's method hides all methods with the same name rather than overriding.  This is what the "ERROR" in your image is attempting to convey.  So, in that image, / overrides in a comment is incorrect and misleading. Yes, many C++ instructors are unaware of these somewhat esoteric details. Furthermore, if you want to override, your base class's method must be virtual; otherwise, polymorphism will not work.  We could also say that the derived-class method hides the base-class method if it wasn't virtual.  The part about hiding, on the other hand, has almost no meaning here; what this term really means is that you're not in charge. Furthermore, overloading is the presence of multiple methods with the same name but different signatures, as you may have noticed. To be useful, they must all be present in the derived class; otherwise, they will be hidden if the derived class only has one method, fa1, and the other fa1 are in the base.  There is, however, a syntax sugar that "copies" all fa1 from the base to the derived. class A { public: void fa1(); ...READ MORE

answered Jun 7, 2022 in C++ by Damon
• 4,960 points
1,082 views
webinar REGISTER FOR FREE WEBINAR X
REGISTER NOW
webinar_success Thank you for registering Join Edureka Meetup community for 100+ Free Webinars each month JOIN MEETUP GROUP