cant get .equals to work

[Hooky75]

Can any one tell me why this won't work for me:

public static void mainMenu()
    {
        String userName, pass, string1;
        Scanner scnr = new Scanner(System.in);
            do{
            System.out.print("Please enter User Name:");
            userName = scnr.nextLine();
           }while(!checkLogin(userName));
                System.out.println("b");
}

public static boolean checkLogin(String userName){
    for(int i = 0; i<users.size(); i++){
        if(userName.equals(users.get(i).getLogin())){
         return true;
        }
       }
      System.out.println("User not found");
      return false;
      }

if use a syso and print the users.get(i).getLogin() i get:

alan
brad
charlie
dan
eric

but if user input is any of the above it still print "User not found".

output so far:

Please enter User Name:alan
User not found
Please enter User Name:brad
User not found
Please enter User Name:charlie
User not found
Please enter User Name:dan
User not found
Please enter User Name:eric
User not found
Please enter User Name:

[DarrylBurke]

To get better help sooner, post a SSCCE (Short, Self Contained, Compilable and Executable) example that demonstrates the problem.

db

[Norm]

Use println to show what is being compared:
System.out.println("testNm=" + users.get(i).getLogin() + "< vs userNm=" + userName + "<");

[Tolls]

What is:

users.get(i).getLogin()

returning?

[Hooky75]

system.out.println(users.get(i).getLogin());

returns

alan
brad
charlie
dan
eric

and userName returns whatever is inputed and they just won't compare even if they are the same string.

And users.get(i).getLogin() is an Arraylist of login, password and id from a text file.

[Tolls]

No.
I mean is it a String?

ETA: Ah, I see it's an arrat list.

So:

userName.equals(users.get(i).getLogin())

Is comparing a String against an ArrayList...which is always going to be false since an ArrayList is not a String.

[Hooky75]

ok is there a way for me to compare them.

[Tolls]

Well, what are you trying to compare exactly?
Once you have defined that, then you can write the comparison.

[Hooky75]

still a newbie at this but am guessing i'm trying to compare an object reference to a string.

[Dark]

Have you looked into casting? If your array list is storing strings, casting it to a string won't remove any information and you will be able to compare them.

[Tolls]

still a newbie at this but am guessing i'm trying to compare an object reference to a string.

That's not what I'm asking.
What are you trying to achieve by this comparison.

What do you want to compare?

Don't think about the code...think about what you are checking for.

Then you can go about trying to figure out how to do that check.

[Hooky75]

i am checking to see if the name entered is in the arraylist.

[Hooky75]

ok thank you all for the help i have found the problem the code i had does work but the arraylist was created from a text file with tokens and the login names were being created with 2 x Space and the end, have added trim() to eack token when reading and it now works.

Once again your help has been greatly appreciated.

[JosAH]

Have you looked into casting? If your array list is storing strings, casting it to a string won't remove any information and you will be able to compare them.

Casting doesn't do anything; have a look:

public class T {
    public static void main(String[] args) throws Exception {

    	Object foo= "fred";
    	String bar= new String("fred");
    	
    	System.out.println(bar.equals(foo));
    	System.out.println(foo.equals(bar));
    }
}

'true' is printed twice, no matter the reference type of the objects. The equals() method of the real type (both String) is used. That's what inheritance and overriding is all about.

kind regards,

Jos

[Dark]

Hmm, well looks like I learned something from this topic. Thanks JosAH.