How to sum an array of numbers using reduce()
Swift version: 5.6
The 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.
BUILD THE ULTIMATE PORTFOLIO APP Most Swift tutorials help you solve one specific problem, but in my Ultimate Portfolio App series I show you how to get all the best practices into a single app: architecture, testing, performance, accessibility, localization, project organization, and so much more, all while building a SwiftUI app that works on iOS, macOS and watchOS.
Sponsor Hacking with Swift and reach the world's largest Swift community!
Available from iOS 8.0
Similar solutions…
- How to use reduce() to condense an array into a single value
- How to use decorative images to reduce screen reader clutter
- How to detect the Reduce Motion accessibility setting
- How to reduce animations when requested
- How to detect when the system is under pressure and you should reduce your work
About the Swift Knowledge Base
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
