CODEWITHSUNDEEP
swift
Michael Rader
Michael Rader

Reputation: 5967

Creating an instance of a class with parameters

In a swift lesson I'm going through it says this is a valid way of creating an instance of a class:

class Heroes
{
    var (name, gender, kingdom) = ("","","")
    var (level, ad, hp) = (0,0,0)

    init(name: String)
    {
        self.name = name
    }
}

The part below is what is causing this error "cannot assign value of type '(name: String)' to type 'Heroes'

let sirGeorge: Heroes
sirGeorge = (name: "Sir George")

The below way works fine but I don't understand the syntax of the way above, nor does the compiler. Is there a new way in Swift 3 of writing this perhaps? 

var sirLance = Heroes(name: "Sir Lancelot")

Upvotes: 0

Views: 99

Answers (4)

PGDev
PGDev

Reputation: 24341

Line 1: let sirGeorge: Heroes

Here you are creating a constant sirGeorge of type Heroes. This is correct. The only value sirGeorge can take must be of type Heroes and nothing else.

Line 2: sirGeorge = (name: "Sir George")

Here you are assigning sirGeorge a value that is of type (name: "Sir George") and not Heroes. So in order to assign value to sirGeorge you need to create an instance of Heroes ,i.e,

sirGeorge = Heroes(name: "Sir George")

This will call the init(name: String) of Heroes.

Upvotes: 0

Soul
Soul

Reputation: 50

when you do this sirGeorge = (name: "Sir George") is like you want to assign (name: "Sir George") to sirGeorge which is wrong because sirGeorge is an object of class Heroes

So this is the right way

sirGeorge = Heroes(name: "Sir George")

because now you are initialising your object. It is like calling init(lets say init function ) and init takes a String "Sir George"

Upvotes: 0

Wilson
Wilson

Reputation: 9136

Because if you want to create the object Heroes, first you need to use the Class Name Heroes then the parenthesis with its arguments (name: "Sir George"), like so:

let sirGeorge: Heroes
sirGeorge = Heroes(name: "Sir George")

Upvotes: 1

Oleg Gordiichuk
Oleg Gordiichuk

Reputation: 15512

let sirGeorge: Heroes

You create constant with let and name sirGeorge and you set that type of the constant is Heroes. It is value reference data type.

sirGeorge = (name: "Sir George")

Second line you try to assign to constant with type Heroes new value that content type '(name: String)' and hear you receive issue. Because you're type is Heroes and not '(name: String)'. In another hand you try to assign to value constructor of the class.

Upvotes: 0

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