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iOS

Michael touboul
Michael touboul
3,053 Points
Posted by Michael touboul
Michael touboul
3,053 Points

Struggling to understand class and struct...

Hello everyone, am I the only one here who is very confused regarding struct and classes...? I understood all the learning parts until Passan started with the "struct" - I am having major difficulty understanding everything, am I the only one here? what can I do to continue, I really need some advice here, thx.

1 Answer

Caleb Kleveter
MOD
Caleb Kleveter
Treehouse Moderator 37,862 Points
Caleb Kleveter
Caleb Kleveter
Treehouse Moderator 37,862 Points

You might want to read this document about choosing a struct or a class.

I don't know if this has been covered at this point in your learning, but the biggest difference you will see in working with classes vs structs is how that actual data is handled when an instance of a type is created.

Let's say I have a User struct:

struct User {
    var name: String
    var age: Int

    init(name: String, age: Int) {
        self.name = name
        self.age = age
    }
}

var userOne = User(name: "Caleb", age: 18)
var userTwo = userOne

userTwo.age = 19

print(userOne.age) // 18
print(userTwo.age) // 19

If I copy the instance of a struct and mutate the copy, the original will not be modified. But If I do the same thing with a class:

class User {
    var name: String
    var age: Int

    init(name: String, age: Int) {
        self.name = name
        self.age = age
    }
}

var userOne = User(name: "Caleb", age: 18)
var userTwo = userOne

userTwo.age = 19

print(userOne.age) // 19
print(userTwo.age) // 19

If I mutate the copy of a class instance, the original is updated. This is one of the biggest noticeable differences between a struct and a class.