Logic in java?

[Wuild]

Like the topic says.
I started developing in java a few days ago (was bored of PHP)

So i started to make some basic apps but now im stuck at one thing...
Let me explain

if(string == string)
IS TRUE
else
IS FALSE

seems logical to me, but my code does not...

for (int i = 0; i < userdata.length; i++) {
	if (userdata[i] != null) {
		System.out.println(userdata[i].names + " => " + name);
		if (userdata[i].names == name) {
			System.out.println("Name already exists");
		} else {
			System.out.println("Does not exists");
		}
	}
}

so my problem lies in the if (userdata[i].names == name)
each user has to register a name apon login.
it has to check if the username is already in use.

when printing out the System.out.println(userdata[i].names + " => " + name);
i get for example
test => test if test is already in use, but the
if (userdata[i].names == name)
says its not equal...

Any replies would be awsome =)

[Wnt2bsleepin]

When comparing strings, you have to use the equals method.

[Wuild]

what do you mean?

Edit: nvm i think i understand ;) silly me

[Wuild]

im guessing you mean like this

name.equals(userdata[i].names)

[Wnt2bsleepin]

Pretty much. Strings are considered objects, so you need to compare the content of the String rather than the object itself.

[Wuild]

Pretty much. Strings are considered objects, so you need to compare the content of the String rather than the object itself.

Yeah i figured it out :) thanks a bunch

[Wuild]

oh so im stuck again on what i think is simple logic...

okey so i can check the equal names from the user handler.

but when i login with 1 username and tries to login on another client with another username, it says that the username already exists...
So some how the scripts sets the name before it checks it....

boolean exists = true;
while (true) {
	String set_name = is.readLine();
		for (int i = 0; i < userdata.length; i++) {
			if (userdata[i] != null) {
				System.out.println(set_name + " => " + userdata[i].names);
				if (set_name.equals(userdata[i].names)) {
				os.println(set_name+" already in use");
				exists = true;
     			        System.out.println("exists");
				break;
		        } else {
				userdata[id].addUser(set_name);
				exists = false;
				System.out.println("does not exists");
			}
		}
				}
		if(!exists){
		        break;
		}
	}
name = userdata[id].names;