c++ initialize char array member of a class with a string - c++

Question

i have a class which has several members of char arrays, and i want to initialize this class with an array of strings which are the values of the char arrays.
class Product {
public:
char productId[20];
char productName[50];
char price[9];
char stock[9];
Product(vector<string> v) : productId(v[0]), productName(v[1]), price(v[2]), stock(v[3]) { }
};
with this code i get an error that say no suitable conversion function from "str::string" to "char[20]" exist

Answer 1

The code at the bottom will work. But is this a good idea? Probably not. You are better of just storing std::string in your Product type directly:
#include <cassert>
#include <iostream>
#include <vector>
#include <string.h>
class Product {
public:
std::string productId;
...
Product(std::vector<std::string> v) : productId{std::move(v[0])} {}
};
There is a problem with this code though; where do you check the vector has all required elements? Better to make an interface that specifies the four strings a Product is made up of separately:
class Product {
public:
std::string productId;
...
Product(std::string pid, ...) : productId{std::move(pid)}, ... {}
};
But in case you insist on a C/C++ amalgamation;
#include <cassert>
#include <vector>
#include <string.h> // strcpy
class Product {
public:
char productId[20];
char productName[50];
char price[9];
char stock[9];
Product(const std::vector<std::string> &v) {
assert(!v.empty()); // really; v.size() == 4
::strncpy(productId, v[0].c_str(), 19);
productId[19] = '\0';
// ...etc.
}
};