Apps Script V8: Maps and Sets – Desktop liberation

Sets and Maps can often be a cleaner way of storing data than using Objects or Arrays, even though at first glance they may seem a little redundant. Unlike an array, they are aware of what else is in the map or set (so you can avoid duplicates), and unlike an object, you can use anything as the key – including the item value itself

Given many Apps Script projects focus on manipulating data Bruce Mcpherson provides a useful introduction to Maps and Sets.

Source: Apps Script V8: Maps and Sets – Desktop liberation