Copy constructor in C++

 A question has been bugging me some time ago - what is a constructor? ? What is a copy constructor again? ?

Because Xiaobo doesn't often use copy constructors and the like in his work, and he belongs to the type that only seeks answers when encountering problems, so. . . (a bit of nonsense)

------------------------gorgeous. . gorgeous. . . . It's a gorgeous dividing line-------------------

I won't explain the constructor here. Let's look at the copy constructor directly. In fact, if you really understand its principle, then your first thought is. . . I rely on, is that so? ?

First of all, from the name, the copy constructor (well, it sounds tall), can actually be divided into two --- copy, constructor

To put it bluntly, when the function is constructed,

Assign other classes to the whole

code below

#include <iostream>
using namespace std;

class productA
{
public:
    productA();//This is the constructor
    productA(productA& item);//This is the copy constructor
private:
    int a;
}；

//Constructor, assign initial value
productA::productA()
{
    this->a = 1;
}

//Yes, yes, this is a copy constructor
productA::product(product* item)
{
    this->a = item->a;
}

//accomplish
int main(int argc, char* argv[])
{
    productA* A = new productA();
    productA* B = new productA(A);
    return 0;
}

　　-------------------------Being too lazy to describe the dividing line-------------------- ---------

If you have any objection to this, please leave a message, exchange and discuss, Xiaobo is very grateful!