how to check if an object already exists

[oll3i]

how to check if an object already exists and return reference to that object

[RedSon]

Can you please describe your question in more detail?

[oll3i]

i have to write a flower shop
i need to check if a client already exists so that i dont add a new one

[hirak1984]

[font=Verdana][size=2]your question is not yet clear.[/size][/font]
[font=Verdana][size=2]In general we compare the instance of the object with null,[/size][/font]
[font=Verdana][size=2]to see if it exists or not...[/size][/font]

i have to write a flower shop
i need to check if a client already exists so that i dont add a new one

[prometheuzz]

i have to write a flower shop
i need to check if a client already exists so that i dont add a new one

Exists in what? An array, a java.util.List some other java.util.Colle ction?

[oll3i]

in a list of clients

[JosAH]

in a list of clients

Well, read all about it in the API docs for the List.contains(. ..) method.

kind regards,

Jos

ps. Bookmark The API docs or download them for easy reference.
Keep those docs at your fingertips whenever you want to write code.

[oll3i]

[code]
if(klienci.cont ains(klient)){
int index=klienci.i ndexOf(klient);

klient=klienci. get(index);
}

[code]

but it doesnt find the client in the list

[hirak1984]

can we know the errors you are getting?

[code]
if(klienci.cont ains(klient)){
int index=klienci.i ndexOf(klient);

klient=klienci. get(index);
}

[code]

but it doesnt find the client in the list

[prometheuzz]

if(klienci.cont ains(klient)){
int index=klienci.i ndexOf(klient);

klient=klienci. get(index);
}

but it doesnt find the client in the list

When doing this, you're looping through the list twice: once in the contains(...) method, and another looptwhen using the indexOf(...) method.
I suggest doing this:

int index = klienci.indexOf(klient);
 
if(index != -1) {
  klient = klienci.get(index);
} 
else {
  // 'klient' is not in the list 'klienci'
}