@Chinedu_Arinze is exactly correct, but I wanted to add a clarifier for @Sarah_Pfeil because the or_other construct does have limitations if you need to support multiple languages or code other as a different value.
In this example below, favorite_colors uses the or_other construct, while favorite_numbers does this manually using relevance.
t9062.xlsx (11.0 KB)
You'll note that favorite_numbers question lets you specify the wording of the other question, the label of the option in whatever language, and what value/name is saved to the database (e.g., -1). You can also specify whatever data type you want. For example, you can have an other that is a GPS coordinate or a picture.
One limitation you should be aware of is that you cannot put favorite_numbers and other_number on the same screen (e.g., in a group with a field-list). They have to appear on different screens.