Converting String into array reference

Question

I have multiple arrays, The first one contains the names of all the other arrays.

So I retrieve the value of the first array I get the name of my desired array but I don't know how to proceed from there. As swift sees my result as a string, not a variable name. I have recreated my problem below

import UIKit
var str = "Hello, playground"
var traits = ["trait one","trait 2", "trait3"]
var trait3 = ["final Answer 0","final Answer 1","final Answer 2","final Answer 3","final Answer 4"]
var counter = 2
let intermediateV = traits[counter]
print(intermediateV[2])

The error I get is:

'subscript' is unavailable: cannot subscript String with an Int

traits[counter] is "trait3", what is intermediateV[2] aka "trait3"[2] supposed to do? Are you trying to get "final Answer 2" - that is not going to work. Use multi-dimensional arrays instead or (even better) structs and classes, do not create variables with counters as part of their name, that is almost always a bad idea. — luk2302
– luk2302, Commented Aug 11, 2017 at 11:07
I am indeed trying to get Final Answer 2. I understand this is not going to work, do you have any suggestions on how to get my desired result? — Ali Abou El Atta
– Ali Abou El Atta, Commented Aug 11, 2017 at 11:09
I cant use multi-dimensional arrays as the first array aka "traits" is downloaded from Firebase. The other array aka "trait3" is stored locally. I need a way to get "Final answer 2" where these two arrays are seperate. — Ali Abou El Atta
– Ali Abou El Atta, Commented Aug 11, 2017 at 11:13
You are trying to replace a variable name with a literal string. This is impossible. Variable names are evaluated at compile time. Put the arrays (the objects) rather than the literal variable names into the array. — vadian
– vadian, Commented Aug 11, 2017 at 11:15

luk2302 · Accepted Answer · 2017-08-11 11:30:52Z

1

If you cannot do multi dimensional arrays you have to use dictionaries:

var traitKeys = ["trait one", "trait 2", "trait3"] // downloaded from somewhere, dynamic

var traits = [
    "trait one" : ["final Answer 0","final Answer 1","final Answer 2","final Answer 3","final Answer 4"], 
    "trait 2" : ["final Answer 0","final Answer 1","final Answer 2","final Answer 3","final Answer 4"], 
    "trait3" : ["final Answer 0","final Answer 1","final Answer 2","final Answer 3","final Answer 4"]
]

let counter = 2
let traitKey = traitKeys[counter]

print(traits[traitKey] ?? "trait not found")

answered Aug 11, 2017 at 11:30

luk2302

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ridvankucuk · Accepted Answer · 2017-08-11 11:13:48Z

1

You are trying to access an element from String intermediateV equals "trait3" in your case. However string subscription is not possible in your case. You can try something like this:

var trait1 = ["trait 0","trait 1","trait 2","trait 3","trait 4"]
var trait2 = ["final Answer 0","final Answer 1","final Answer 2","final Answer 3","final Answer 4"]
var trait3 = ["final Answer 0","final Answer 1","final Answer 2","final Answer 3","final Answer 4"]

var traits = [trait1, trait2, trait3]

var counter = 2

let intermediateV = traits[counter]

print(intermediateV[2])

answered Aug 11, 2017 at 11:13

ridvankucuk

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1 Comment

Ali Abou El Atta Over a year ago

As I mentioned in the comments, I cant do multi-dimensional arrays as the first array "traits" is downloaded from the internet so it has values of strings inside it. I need to use those strings to lookup my other locally stored arrays

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