Some example noob code i'm playing with.

[mtod1]

Hi all.

This is my first post. I am completely new to coding and have been messing about with C++ for about a week or so now and thought I'd post some code I have been messing about with. Feel free to make suggestions or cut 'n' paste etc.

This bit of code asks for a username and checks against a stored string. If the username if wrong it loops otherwise a correct username causes goto to break the loop and end the prog.

#include <iostream>
#include <string>

using namespace std;

int main()

{
    string user;
    do {                                        //Beginning of do-while
        cout << "What is your username? ";
        getline (cin, user);                    //username input is stored as a string
        if (user=="mark")                       //Correct username will end do-while
        goto loggedin;                          //Jump to loggedin
    } while (user!="mark");                     //Loop continues until right username is entered
    loggedin:
    cout << "You are now logged in! ";          //end of do-while as a result of correct username.
    return 0;
}

This second bit of code is an attempt to validate a username and password using if and else. I really should change all the cin references to getline (cin,string) but it works anyway.

#include <iostream>
#include <string>

using namespace std;

int main()

{
    string name, pword;

    cout << "Please enter your username: ";
    cin >> name;
    if (name!="mark")
    cout << "Incorrect username ";
    else
    cout << "Please enter your password ";
    cin >> pword;
    if (pword!="test")
    cout <<  "Incorrect password ";
    else
    cout << "You are now logged in! ";
    return 0;
    }

My next step is to combine both bits of code and develop a single prog that will ask for a username and password and continue to loop until both strings are correct. After that I'll have to work out how to limit the number of attempts at the username and/or password. (no hints thanks)

[screw]

Hi!

In your first code you should avoid the goto. Look at the get out of the loops? topic.

In your second code you should use the braces.

Like this:

#include <iostream>
#include <string>

using namespace std;

int main()

{
    string name, pword;

    cout << "Please enter your username: ";
    cin >> name;
    if (name!="mark")
       cout << "Incorrect username ";
    else
    {
       cout << "Please enter your password ";
       cin >> pword;    
       if (pword!="test")
          cout <<  "Incorrect password ";
       else
         cout << "You are now logged in! ";
    
    }
    return 0;
}

[bluezor]

@screw,

Just some logic flaws in your code example:
If the username was correct, nothing will happen.
Also, if the username was wrong but the password was correct, the user is still logged in.

---

I'd probably do something like this -

do
{
    cout "enter username"
    get the name;
    if (name is username)
        break; //breaks out of the loop
    cout "invalid username" //shouldn't get here unless the username is invalid
} while (name != username);

and a similar process for the password.

[mtod1]

Is this better? I removed the goto and replaced it with Break.

#include <iostream>
#include <string>

using namespace std;

int main()

{
    string user;
    do {                                        //Beginning of do-while
        cout << "What is your username? ";
        getline (cin, user);                    //username input is stored as a string
        if (user=="mark")                       //Correct username will end do-while
        break;                                  //Break loop if username is correct
    } while (user!="mark");                     //Loop continues until right username is entered
    cout << "You are now logged in! ";          //end of do-while as a result of correct username.
    return 0;
}

[tummychow]

Kind of but is that really necessary? Why not just do this?

do
{
cout << "What is your username? ";
getline(cin,user);
if (user == "mark")
cout << "You are now logged in! ";
}
while (user != "mark");

As noted in other threads goto is really bad style; break is condonable in some cases but I wouldn't say it's worth it in this situation.

[mtod1]

Here is my current code for users to enter and confirm their username and password. I'm a complete noob so comments appreciated. ;)

#include <iostream>
#include <string>

using namespace std;

int main()

{
    string auser, apword, buser, bpword;

    cout << "\n\t==========================";
    cout << "\n\tUsername and Password Prog ";
    cout << "\n\t==========================";
    cout << "\nPlease enter a username \n";
    getline (cin,auser);
    cout << "Please enter a password \n";
    getline (cin, apword);
    cout << "\t============================= ";
    cout << "\n\tUsername and Password Check \n";
    cout << "\t============================= \n";
        do {
            cout << "Please confirm your username \n";
            getline (cin, buser);
                {
                    if (buser!=auser)
                    cout << "That username is incorrect. \n";
                }
            }while (buser!=auser);

        do {
            cout << "Please confirm your password \n";
            getline (cin,bpword);
                {
                    if (apword!=bpword)
                    cout << "That password is incorrect. \n";
                }
            }while (bpword!=apword);
        cout << "You are now logged in. \n";
    return 0;
}