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iOS Swift Enums and Structs Structs and their Methods Struct Methods

Posted by Guilherme Kunzler
Guilherme Kunzler
1,433 Points

Removing "self"

I've removed all "self"s from my code and it still works.

We use self for best practice? Or there is something I didn't learn in the course yet that will make self more useful?

*************************** CODE ************************

struct Contact {

let firstName: String
let lastName: String
var type: String

init(fName: String, lName: String){

    firstName = fName
    lastName = lName
    type = "Friend"

// self.firstName = fName // self.lastName = lName // self.type = "Friend"

}

func fullName() -> String {
    return firstName + " " +  lastName
}

func findType ()-> String{
    return type
}

}

var person = Contact(fName: "gui", lName: "maia") person.fullName() person.findType()

2 Answers

Lauren Hibbs
Lauren Hibbs
1,872 Points
Lauren Hibbs
Lauren Hibbs
1,872 Points

Self is useful mainly when and object is passing a reference of itself to another class, function, etc. It isn't necessary within a class because it already has access to all of its properties and functions. 

struct School {
    var name : String
    var students: [Student] = []

    init(schoolName : String){
        students = []
        name=schoolName
    }

    mutating func addStudent(student : Student){
        students.append(student)
    }
}

struct Student{
    var name :String
    var aSchool :School

    mutating func enroll(){
        aSchool.addStudent(self)
    }
}

var mySchool = School(schoolName:"Random School")
var person = Student(name:"Lauren", aSchool:mySchool)
person.enroll()

My experience is in Java, not Swift, so this might be a little complicated but hopefully it is right. Hope this helps!

Ryan Ebbers
Ryan Ebbers
3,746 Points
Ryan Ebbers
Ryan Ebbers
3,746 Points

From my understanding of the keyword "self", it explicitly says that you are targeting the property of a specific Struct instance. Using Amit's Car example, "self" declares that you are working with this Car instance and not one of the other instances.

On a side note, I started to remove "self" from my playground to see if it still worked on my computer. It still worked, but only after modifying the init() method parameter names (I was using "firstName" and "lastName", and changed them to "fName" and "lName"). As Amit said in the previous course, it is good practice to use descriptive parameter names.

In closing, using the "self" keyword targets that exact instance and allows you to use the same variable and parameter name (when you prepend "self" to the variable name) within the init() method.

Hope this helps.