How to sum an array of numbers using reduce()
Swift version: 5.0
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.
LEARN SWIFTUI FOR FREE I wrote a massive, free SwiftUI tutorial collection, and also have a growing list of free SwiftUI tutorials on YouTube – get started today!
Available from iOS 8.0
Did this solution work for you? Please pass it on!
Other people are reading…
- How to find the longest initial sequence in an array
- What is a protocol?
- What are designated initializers?
- How to use ISO-8601 dates with JSONDecoder and Codable
- What’s the difference between a function and a method?
About the Swift Knowledge Base
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
