CODEWITHSUNDEEP
javalistarraylistmethods
DDDD
DDDD

Reputation: 153

Find if in a list of a class defined by me exists an element with given variables values

I have defined the class User:

    public class User
    {
        public String id;
        public String passWord;

        public User(String id, String passWord)
        {
            this.id = id;
            this.passWord = passWord;
        }
    }

Then I created a list of Users:

public static void main(String[] args) {

    List<User> users = new ArrayList<User>();
    users.add(new User("u1", "abc"));
    users.add(new User("u2", "aaa"));
    users.add(new User("u3", "bba"));

To find the user in the list with a given id and password I did:

Scanner input = new Scanner(System.in);
System.out.print("User: ");
String user = input.next();
System.out.print("Password: ");
String pass = input.next();
int N = -1;
for (int n = 0; n < medicos.size(); n++)
{
    if (user.equals(users.get(n).id) && pass.equals(users.get(n).passWord))
        {
            N = n;
        }
    }

Is there a simpler way to get the element of the list containing the given id and password, for example like using a method similar to contain?

Upvotes: 0

Views: 43

Answers (1)

Alex Parker
Alex Parker

Reputation: 1583

Use a HashMap. You can still use an ArrayList of User if you want, but you could also add the username and password to a HashMap with the username as the key and the password as the value. So, for instance, you could do something like this:

Map<String, String> users = new HashMap<>();
users.put("u1", "abc");
users.put("u2", "aaa");
users.put("u3", "bba");

Scanner input = new Scanner(System.in);
System.out.print("User: ");
String user = input.next();
System.out.print("Password: ");
String pass = input.next();

String pword;
if (users.containsKey(user)) {
    pword = users.get(user);
}

Now the variable pword contains the password for the user named "user" (obtained from the Scanner).

Upvotes: 2

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