Swift version: 5.1
reduce() method is designed to convert a sequence into a single value, which makes it perfect for calculating the total of an array of numbers.
For example, given the following number array:
let numbers = [1, 12, 2, 9, 27]
We could calculate the total of all those numbers like this:
let total = numbers.reduce(0, +)
The first parameter passed to
reduce() is the value it should start with, in this case 0. The second parameter is how it should combine that 0 with each item in your array, which means it will do 0 + 1 to make 1, then 1 + 12 to make 13, and so on.
SPONSORED Why the top iOS apps rely on Instabug for crash reporting. Crash reporting + Bug reporting + Customizable in-app surveys all in one SDK. Know which line of code caused the crash along with network logs, repro steps, and the session profiler to identify and resolve severe crashes quickly. See more detailed features comparison and try Instabug for free here.
Available from iOS 8.0
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.