How do I add a previous stated variable inside of a let command

Question

I was wondering how I could call upon previously stated variables inside of a let. I'm using Xcode Version 8.3.2 (8E2002).

I have created a TableView which shows my players (bees) and current levels. I would like to be able to upgrade a specific player, without it affecting the other players.

Here is my current coding for the table view:

ViewController.swift

import UIKit

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

var beelevel = 0
var wasplevel = 0
var bumblebeelevel = 0

let bees = ["bee", "wasp", "bumblebee"]
let beeslevel = [beelevel, wasplevel, bumblebeelevel]

When I try using variables in the let command, it returns "Cannot use instance member 'bee level' within property initializer; property initializers before 'self' is available"

Please [search on an error](https://stackoverflow.com/search?q=%5Bswift%5D+Cannot+use+instance+member+within+property+initializer%3B+property+initializers+before+%27self%27+is+available) before posting. — rmaddy, May 31 '17 at 14:42

score 1 · Answer 1 · answered May 31 '17 at 08:07

1

You cant use instance member while declaring coz self have not fully init yet:

let beeslevel = [beelevel, wasplevel, bumblebeelevel]

But you can use computed property:

var beeslevel: [Int] {
    return [beelevel, wasplevel, bumblebeelevel]
}

answered May 31 '17 at 08:07

Tj3n

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score 1 · Answer 2 · answered May 31 '17 at 08:08

Variables declared like that are not initialized in any specific order, so there's no way to be sure that beeLevel will be available when initializing beesLevels.

What you can do is override the initializers, there should be two for a UIViewController:

override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
}

required init?(coder aDecoder: NSCoder) {
}

Initialize your beesLevels constant in there and then call super.

PS. Just a heads up, even if you change the "levels" variables, you'll always get an array of 0s on your beesLevels array, because it's the value that's being stored, not a pointer to the variable.

If you want that array to always be up to date with those values you can declare it like this:

var beesLevels: [Int] { return [beelevel, wasplevel, bumblebeelevel] }

I'm new to swift so I'm not quite sure what you're insisting i do... Is there anyway you could possibly be clearer? Thanks — Traxido, May 31 '17 at 08:33

score 0 · Answer 3 · answered May 31 '17 at 11:03

0

You can use lazy initialization to achieve this:

 lazy var beeslevel:[Int] = [self.beelevel, self.wasplevel, self.bumblebeelevel]

answered May 31 '17 at 11:03

Alain T.

40,517
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How do I add a previous stated variable inside of a let command

3 Answers3