Beginner Android why is “id” is “Unknown member” with R.id?

Question

I\'m sure this is something dead simple as it\'s my first android app with code (the hello world example I did was just assigning a value to a string in XML). My problem is

Answer 1

You must add id to a component in the XML file. Like this:

android:id="@+id/buton1"

Now can you click mainActivity.java and write code "R.id." you a see hint to write "buton1" and no error of "id"