what is ids.xml used for?

Question

Just a quick question, what is the ids.xml used for when developing an Android app? I saw an example on the android resources webpage which contained:

Answer 1

ids.xml is much more powerful. You can predefine values like

not only id. Actually you can use more resource types: https://developer.android.com/guide/topics/resources/more-resources

It's extremely helpful to predefine some layouts, colors etc. in root module for multi-module app. You can keep actual layouts, colors, etc. in specific app module which has root module as dependency.