Invalid array assignment?

Question

When I run the code below I get the error : invalid array assignment on lines 14 and 26. I am fairly new (1 week) to c++ so I am a bit confused. I searched and could not find an answer to solve my problem.

#include <iostream>
int main()
{
 using namespace std;
 char usrname[5];
 char psswrd[9];
 cout << "Please enter your username:";
 cin >> usrname;
 if (usrname = "User")
 {
 cout << "Username correct!";
 }
 else 
 {
 cout << "Username incorrect!";
 }
 cout << "Please enter your password:";
 cin >> psswrd;
 if (psswrd = "password")
 {
 cout << "The password is correct! Access granted.";
 }
 else 
 {
 cout << "The password is incorrect! Access denied.";
 }
 return 0; 
}

• Qaz: Use std::string to start with. Even with the right number of equals signs, it's still wrong with character arrays.

Answer 1

You can't assign arrays, and

usrname = "User"

does just that. Don't.

You meant

usrname == "User"

which is a comparison, but won't compare your strings. It just compares pointers.

Use std::string instead of char arrays or pointers and compare with ==:

 #include <string>
 //...
 std::string usrname;
 cin << usrname;
 if (usrname == "User")
 // ^^
 // note == instead of =

Side question - what's the point of shortening "username" to "usrname"... you're saving a single character...

• DmitryK: using == operator when comparing strings is wrong, you should use str1.compare(str2), for more information read : cplusplus.com/reference/string/string/compare
• Luchian Grigore: @DmitryKvochkin it's not wrong. Why would you say that? This isn't Java... It's perfectly OK to compare std::strings with == in C++.
• user529758: @DmitryKvochkin Have you heard about operator overloading? Probably std::string::operator== uses strcmp() under the hoods...
• Benjamin Lindley: @DmitryKvochkin: From the same site: cplusplus.com/reference/string/operators
• zachpescitelli: Thank you so much @Luchian Grigore! An to answer your side question: honestly I don’t know I guess that’s just how I typed it.

Answer 2

you need to use strcmp or similar.

if (!strcmp(usrname, "User"))
{
 cout << "Username correct!";
}

what you are doing is assigning a value not comparing values.