Trending questions in C++

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When to use virtual destructors?

When you want to delete an instance of a derived class using a pointer to the base class, virtual destructors come in handy: class Base { // ...READ MORE

Jun 7, 2022 in C++ by Damon
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Function default argument value depending on argument name in C++ [duplicate]

When the function is called with no argument for the corresponding parameter, the default argument is evaluated.  In a default argument, a parameter must not appear as a potentially evaluated expression.  A function's parameters declared before a default argument are in scope and can obscure the namespace and class member name. It provides the following example: int h(int a, ...READ MORE

Jun 7, 2022 in C++ by Damon
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What data structure is inside std::map in C++?

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

May 31, 2022 in C++ by Damon
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Code Not working in VS Code but works in OnlineGDB

I am practicing about primeSieve with C++ language in VS Code 1.57.1. Can ...READ MORE

Jun 1, 2022 in C++ by Nicholas
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static memory allocation like dynamic memory allocation

int r, c; cin >> r >> c; int ...READ MORE

Jun 6, 2022 in C++ by Nicholas
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386 views
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functions in c++ call by value and call by reference

The code below shows how to call a function in both methods.  Please explain the major differences or meanings of call by value and call by reference to me.  1.Make a value-based call.  2.Call based on a reference.  The call by value method is demonstrated in the following code. In a comment, I expressed my reservations. #include<iostream> int main(){ void change(int);//why function prototype is before ...READ MORE

Jun 6, 2022 in C++ by Nicholas
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The new syntax "= default" in C++11

A defaulted default function Object() { [native code] } is defined as a user-defined default function Object() { [native code] } with an empty compound statement and no initialization list. I'll give you an example to demonstrate the difference: #include <iostream> using namespace std; class A { public: ...READ MORE

Jun 7, 2022 in C++ by Damon
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How can I convert a std::string to int?

There are some new convert methods in C++ that convert std::string to a numeric type. As an alternative to str.c str() atoi(str.c str()) atoi(str.c str() you can make use of std::stoi std::stoi ...READ MORE

Jun 1, 2022 in C++ by Damon
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why are copy constructors needed and what are the cases where they are very helpful?

A copy constructor is a member function ...READ MORE

May 31, 2022 in C++ by Damon
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565 views
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Intersection of two std::unordered_map

I have two std::unordered_map std::unordered_map<int, int> mp1; std::unordered_map<int, int> ...READ MORE

May 31, 2022 in C++ by Nicholas
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552 views
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C++ "Object" class

No, there is no generic base class&nb ...READ MORE

Jun 2, 2022 in C++ by Damon
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Use of min and max functions in C++

Are std::min and std::max better than fmin ...READ MORE

Jun 2, 2022 in C++ by Nicholas
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386 views
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How to reverse an std::string?

A reverse function is integrated into C++ and can be used to reverse a string.  This function accepts two parameters: The start iterator for the string The string iterator has come to an end. The following line of code demonstrates how to use this function: #include <iostream> //The library below must be included ...READ MORE

Jun 1, 2022 in C++ by Damon
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What is a smart pointer and when should I use one?

A smart pointer is similar to a ...READ MORE

Jun 2, 2022 in C++ by Damon
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321 views
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How to implement 2D vector array?

I'm using the vector class in the ...READ MORE

Jun 1, 2022 in C++ by Nicholas
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383 views
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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

May 31, 2022 in C++ by Damon
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What is the C++ function to raise a number to a power?

What's the best way to raise a n ...READ MORE

Jun 1, 2022 in C++ by Nicholas
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348 views
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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
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288 views
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1 answer

C++ `this` pointer

Pointer variables are used to store the ...READ MORE

May 31, 2022 in C++ by Damon
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407 views
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Syntax of priority queue

We must first include the queue header file in order to establish a priority queue in C++. #include <queue> Once we import this file, we ...READ MORE

May 31, 2022 in C++ by Damon
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369 views
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How to implement 2D vector array?

I'm using the vector class in the ...READ MORE

Jun 1, 2022 in C++ by Nicholas
• 7,760 points
299 views