Vikas Patidar Vikas Patidar - 1 year ago 49
Android Question

Difference between "@id/" and "@+id/" in Android

What is the diffirence between the

the plus symbol + instructs to create a new resource name and add in to the
file but what about
? From the documentation of
: when referencing an Android resource ID, you do not need the plus symbol, but must add the android package namespace, like so:


But in the image below Eclipse doesn't suggest any kind of

Image showing the suggestion for the @/id and @+/id

the same?

Answer Source

you refer to Android resources , which are already defined in Android system, with @android:id/.. while to access resources that you have defined/created in your project, you use @id/..

More Info

As per your clarifications in the chat, you said you have a problem like this :

If we use android:id="@id/layout_item_id" it doesn't work. Instead @+id/ works so what's the difference here? And that was my original question.

Well, it depends on the context, when you're using the XML attribute of android:id, then you're specifying a new id, and are instructing the parser (or call it the builder) to create a new entry in, thus you have to include a + sign.

While in the other case, like android:layout_below="@id/myTextView" , you're referring to an id that has already been created, so parser links this to the already created id in

More Info Again

As you said in your chat, note that android:layout_below="@id/myTextView" won't recognize an element with id myTextViewif it is written after the element you're using it in.