Swift tip: Building arrays with compactMap
29 July 2018
A common scenario in app development is to build up a list of objects, perhaps to display to the user or for another purpose. Maybe you’re fetching data from a database to display, or constructing fields to display for an interface. Consider the iOS Calendar app, for example. When you add a new calendar event, the form displays all the fields you can fill-in — title, location, date and time, notes, etc. However, when viewing an existing event all you see are the completed fields while the uncompleted fields are hidden.