What's the difference between struct and typealias in swift?

Question

I want to have an array with one string and one integer in it. What's the difference between:

struct People { var name: String!; var age: Int! };
var data = Array<People>();
data.append (People(name: "John Doe", age: 31));

with:

typealias People = (name: String!, age: Int!);
var data = Array<People>();
data.append ((name: "John Doe", age: 31));

in terms of everything other than that. I mean, is there any difference in accessing the data, memory management, pointer-issue things, or something else I should be wary of when switching from struct to typealias? I usually use struct, but then I just found that I have typealias as alternative. I just want to make sure which one is better for my daily use. Note: I notice that struct is much like class in terms of you can add methods in there. But for things like that, I usually straight up using class.

Answer 1

You are comparing a struct with the typealias of a tuple.

A struct is much more powerful than a tuple, here's some advantages only a struct offers

1. a struct can conform to a protocol, a tuple can't
2. a struct can have methods, a tuple can't
3. a struct can have computed properties, a tuple can't
4. a struct can have initializers, a tuple can't

Considerations

I suggest you to use a struct for your model. It's a better fit for a model value.

Someday you'll need to add a computed property (like birthYear) to your type and you don't want to be constrained by the limitations of simple tuple.