Using the split function in Swift 2

Question

Let's say I want to split a string by an empty space. This code snippet works fine in Swift 1.x. It does not work in Swift 2 in Xcode 7 Beta 1.

var str = "Hello Bob"
var foo = split(str) {$0 == " "}

I get the following compiler error:

Cannot invoke 'split' with an argument list of type '(String, (_) -> _)

Anyone know how to call this correctly?

Updated: Added a note that this was for the Xcode 7 beta 1.

ABakerSmith · Accepted Answer · 2017-01-24T12:14:37.970

126

split is a method in an extension of CollectionType which, as of Swift 2, String no longer conforms to. Fortunately there are other ways to split a String:

Use componentsSeparatedByString:
```
"ab cd".componentsSeparatedByString(" ") // ["ab", "cd"]
```
As pointed out by @dawg, this requires you import Foundation.
Instead of calling split on a String, you could use the characters of the String. The characters property returns a String.CharacterView, which conforms to CollectionType:
```
" ".characters.split(" ").map(String.init) // ["", ""]
```
Make String conform to CollectionType:
```
extension String : CollectionType {}

"w,x,y,z".split(",") // ["w", "x", "y", "z"]
```
Although, since Apple made a decision to remove String's conformance to CollectionType it seems more sensible to stick with options one or two.

In Swift 3, in options 1 and 2 respectively:

componentsSeparatedByString(:) has been renamed to components(separatedBy:).
split(:) has been renamed to split(separator:).

edited Jan 24 '17 at 12:14

answered Jun 10 '15 at 14:27

ABakerSmith

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Thanks. That was helpful. – Mallioch Jun 10 '15 at 14:40
1

It would seem that option #2 is possibly the intended replacement for the removal of `Sliceable`. – Andrew Jul 30 '15 at 02:35
1

Option #1 needs `import Foundation`, no? – dawg Dec 14 '15 at 02:16
2

It's worth noting that option 1 and option 2 are not the same. For example, if the string/character you are separating by appears at the beginning of the string, option 1 will return an array with an additional empty string in index 0, where option 2 will not. – Zig Mar 09 '16 at 23:10
The split option generates a memory leak (in xCode8 at least). Once I replaced my split line for the componentsSerparateByString the memory leak was gone. – Loebre Sep 16 '16 at 08:41
1

About your 2nd solution: You are getting a collection of *characters* and then you split them by where ever you find `" "`. I am not sure I understand the rest. So then you try to use a *String* constructor to convert to a String/human readable value? What's with the `init`? shouldn't it instead be something like `String($0)`? – mfaani Oct 03 '16 at 22:25

score 18 · Answer 2 · edited Jun 20 '20 at 09:12

18

Swift 4

let str = "Hello Bob"
let strSplitArray = str.split(separator: " ")
strSplitArray.first!    // "Hello"
strSplitArray.last!     // "Bob"

Xcode 7.1.1 with Swift 2.1

let str = "Hello Bob"
let strSplit = str.characters.split(" ")
String(strSplit.first!)
String(strSplit.last!)

edited Jun 20 '20 at 09:12

Community

1
1

answered Dec 09 '15 at 06:30

Warif Akhand Rishi

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What if the string has more than one spaces between the two words ? – zulkarnain shah Oct 17 '16 at 07:02
@zulkarnainshah same result. – Warif Akhand Rishi Oct 17 '16 at 09:04

Nirav D · Answer 3 · 2016-10-06T05:22:32.610

9

In Swift 3 componentsSeparatedByString and split is used this way.

let splitArray = "Hello World".components(separatedBy: " ") // ["Hello", "World"]

split

let splitArray = "Hello World".characters.split(separator: " ").map(String.init) // ["Hello", "World"]

edited Oct 06 '16 at 05:22

answered Sep 27 '16 at 10:00

Nirav D

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Using the split function in Swift 2

3 Answers3

Swift 4

Xcode 7.1.1 with Swift 2.1

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