Swift 4: Cannot subscript a value of type 'String' with an index of type 'CountablePartialRangeFrom'

Question

So I have this swift code:

func didReceiveResponse(response:String) {
  ...
  let substr = response[11...]

By my interpretation, substr should be a Substring referencing all characters after index 11 in the response string.

What actually happens is this compiler error:

Cannot subscript a value of type 'String' with an index of type 'CountablePartialRangeFrom<Int>'

This seems like it should be obvious, can anyone help please?

`String` is indexed by `String.Index`, not `Int` – see for example https://stackoverflow.com/q/39676939/2976878 — Hamish, Nov 14 '17 at 23:37

Orion Edwards · Accepted Answer · 2017-11-28T06:30:35.873

10

Whoops. Seems I needed to just do this:

let idx = response.index(response.startIndex, offsetBy: 11)
let substr = response[idx...]

edited Nov 28 '17 at 06:30

answered Nov 14 '17 at 23:38

Orion Edwards

17

You could also say `let subsets = response.dropFirst(11)` :) – Hamish Nov 14 '17 at 23:39

1 Answers1