Instruct Your View With A ViewModel: Should It Be A Class or a Struct?

Another choice?

Photo by Drew Saurus on Unsplash

Difficulty: Beginner | Easy | Normal | Challenging

This article has been developed using Xcode 12.0.1, and Swift 5.3

Terminology:

struct: An object defined in Swift, using pass by value semantics

class: An object that defines properties and methods in common

Prerequisites

- Be able to create a basic Swift application

- You might also like to see the following video to help you out with the differences between Structs and Classes — https://youtu.be/xhfXJ7a2LG8

There are a couple of different ways you can create your ViewModel if you implement the MVVM architecture.

If you’d prefer a video, don’t worry — I’ve got you covered: https://youtu.be/xhfXJ7a2LG8

A comparison project

I’ve created a simple project that has one view using a class for the view model, and one using a struct for the view model.

We can see the two view models (see the rather rubbish function that can print to the console).

and

which is then used in turn from the view controllers:

and