CODEWITHSUNDEEP
swiftstringloopssubstringswift-playground
Eric
Eric

Reputation: 893

looping through substrings in Swift 3.0

What is the best way to loop through a substring in Swift 3.0? 

var start = s.startIndex
var end = s.index(s.endIndex, offsetBy: -10)
   for i in start...end {


   }

The following code throws an error: Type ClosedRange<String.Index> (aka ‘ClosedRange<String.CharacterView.Index>’) does not conform to Sequence protocol.

Upvotes: 1

Views: 471

Answers (2)

vadian
vadian

Reputation: 285072

String.Index cannot be used in a for loop, but (sub)strings can be enumerated

var start = s.startIndex
var end = s.index(s.endIndex, offsetBy: -10)
for (index, character) in s[start...end].enumerated() {
    print(index, character)
}

Upvotes: 0

Willjay
Willjay

Reputation: 6459

start and end are types of String.Index, and they cannot be used in a for loop; instead, you can get substring within the following range:

var start = s.startIndex
var end = s.index(s.endIndex, offsetBy: -10)
let range = Range(uncheckedBounds: (lower: start, upper: end))
let subString = s.substring(with: range)

Upvotes: 2

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