NEW: Get your ticket for Hacking with Swift Live 2019! >>

Remove all instances of an object from an array

Swift version: 5.0

Paul Hudson    @twostraws   

Arrays already have methods to find and remove a single item, or remove all items at once, but for removing all instances of a specific item you need to use a closure-based method called removeAll(where:).

For example, given these numbers:

var numbers = [2, 1, 2, 3, 2, 4, 2, 5]

If we wanted to remove all instances of 2 from that array, we could use removeAll(where:) like this:

numbers.removeAll { $0 == 2 }

If you want to return the array with items removed rather than doing it in place, you’d need to write your own extension to Array, like this:

extension Array where Element: Equatable {
    func removing(_ obj: Element) -> [Element] {
        return filter { $0 != obj }
    }
}

Now you can write let removed = numbers.removing(2) to get back [1, 3, 4, 5].

SPONSOR Tired of wasting time debugging your Swift app? Instabug’s SDK is here to help you minimize your debugging time by providing you with complete device details, network logs, and reproduction steps with every bug report. All data is attached automatically. It only takes a line of code to setup. Get started for free.

Available from iOS 8.0

Did this solution work for you? Please pass it on!

Other people are reading…

About the Swift Knowledge Base

This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.

MASTER SWIFT NOW
Buy Testing Swift Buy Practical iOS 12 Buy Pro Swift Buy Swift Design Patterns Buy Swift Coding Challenges Buy Server-Side Swift (Vapor Edition) Buy Server-Side Swift (Kitura Edition) Buy Hacking with macOS Buy Advanced iOS Volume One Buy Advanced iOS Volume Two Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with Swift Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Beyond Code

Was this page useful? Let me know!

Average rating: 5.0/5

Click here to visit the Hacking with Swift store >>