how to store character variable into two dimensional character variable - c++

Question

I Want to store the value of user_uname and user_pwd to validuser[c][0] and validuser[c][1].Also string "normaluser" to validuser[c][2].
But it shows an error "cannot convert char * to char".This is my code:
char validuser[20][20];
int c;
char user_uname[20],user_pwd[20];
cout<<"\n Enter User Detail";
cout<<"\n enter Username:";
cin>>user_uname;
cout<<"\n Enter Password:";
cin>>user_pwd;
validuser[c][0] = user_uname;
validuser[c][1] = user_pwd;
validuser[c][2] = "normaluser";
c++;

Answer 1

Your validuser is an array of arrays or chars. You can only store single char in each spot, or you can use it as an array of "strings" (char arrays). If you definitely want to use C style strings, you should have a third dimension to do what you're trying, such as char validuser[20][3][20].
But since you are using C++, why not use std::vector<std::string> rather? And store usernames and passwords in a struct, not as consecutive strings. Using C++ strings and vectors will allow you to use any length of strings or any number of users without knowing the number beforehand or handling memory allocations yourself.

Answer 2

char validuser[20][20];
....
validuser[c][0] = user_uname;
The validuser[][] is a char so you are not OK to assign. In your code, you can use:
strncpy( &(validuser[c][0]), user_uname, 20 );
But why dont you use the std::vector or std::array? In most of the case, std::string provide good enough feature for you.

Answer 3

You must use string on this. Char only accept a single character, here is the modified code. Hope this helps :)
The First Dimension you only need 3 array because of the user name, password, and type. for the 2nd Dimension you can add as many as you want, I made it 3 so that it would accept 3 users.
#include<iostream>
#include<string>
using namespace std;
void main()
{
int pause;
string validuser[3][3];
int c = 0;
do
{
string user_uname, user_pwd;
cout << "\nEnter User Detail";
cout << "\nenter Username:";
cin >> user_uname;
cout << "Enter Password:";
cin >> user_pwd;
cout << endl;
validuser[c][0] = user_uname;
validuser[c][1] = user_pwd;
validuser[c][2] = "normal_user";
c++;
} while (c < 3);
c = 0;
do{
cout << validuser[c][0] << " " << validuser[c][1] << " " << validuser[c][2] << endl;
c++;
} while (c < 3);
cin >> pause;
}