How to encode ''+' character in url string?

Question

I want to encode the + character in my url string, I tried to do that this way:

let urlString = "www.google.com?type=c++"

let result = string.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)

but this won't work for +.

any idea? Thanks.

Update:

What's more this type= parameter in the url is dynamic, I wouldn't do some implicite replacement on the + character. This type= parameter represents a UITextField value, so there can be typed-in anything.

I'm also curious why addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed) won't work in this particular case?

Can you use **urlString.replaceOccourences(of: "+", with:"")** ? — Mr. Xcoder, Jan 17 '17 at 12:53
Please check [this](http://stackoverflow.com/a/41568692/6541007). — OOPer, Jan 17 '17 at 13:02
Please read update. I won't do replacement of characters in this case — Robert, Jan 17 '17 at 13:06
It won't work, because `+` is perfectly valid character for `url query string`, it's `url encoded` version of `[space]`. — user28434'mstep, Jan 17 '17 at 14:29

score 6 · Accepted Answer · answered Jan 17 '17 at 13:11

6

let allowedCharacterSet = CharacterSet(charactersIn: "!*'();:@&=+$,/?%#[] ").inverted

if let escapedString = "www.google.com?type=c++".addingPercentEncoding(withAllowedCharacters: allowedCharacterSet) {
  print(escapedString)
}

Output:

www.google.com%3Ftype%3Dc%2B%2B

answered Jan 17 '17 at 13:11

Viktor Gardart

3,782
3
17
24

Yes, your approach is well enough (not ideal), but I'm curious why `addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)` won't work... – Robert Jan 17 '17 at 13:19
That's something i can't answer, they've probably not added the `+` to that for some good reason. – Viktor Gardart Jan 17 '17 at 13:21

score 3 · Answer 2 · answered Jul 09 '21 at 11:05

Swift 5

Using an Extension and add the plus to the not allowed Characters, so you can create your own characterSet and reuse it everywhere you need it. :

extension CharacterSet {
    
    /// Characters valid in part of a URL.
    ///
    /// This set is useful for checking for Unicode characters that need to be percent encoded before performing a validity check on individual URL components.
    static var urlAllowedCharacters: CharacterSet {
        // You can extend any character set you want
        var characters = CharacterSet.urlQueryAllowed
        characters.subtract(CharacterSet(charactersIn: "+"))
        return characters
    }
}

Usage:

let urlString = "www.google.com?type=c++"

let result = urlString.addingPercentEncoding(withAllowedCharacters: .urlAllowedCharacters)

I found a list with the character sets for url encoding. The following are useful (inverted) character sets:

URLFragmentAllowedCharacterSet  "#%<>[\]^`{|}
URLHostAllowedCharacterSet      "#%/<>?@\^`{|}
URLPasswordAllowedCharacterSet  "#%/:<>?@[\]^`{|}
URLPathAllowedCharacterSet      "#%;<>?[\]^`{|}
URLQueryAllowedCharacterSet     "#%<>[\]^`{|}
URLUserAllowedCharacterSet      "#%/:<>?@[\]^`

Source: https://stackoverflow.com/a/24552028/8642838

score 1 · Answer 3 · answered Jan 17 '17 at 12:55

1

Replace + with %2B

let urlString = "www.google.com?type=c++"
let newUrlString = aString.replacingOccurrences(of: "+", with: "%2B")

answered Jan 17 '17 at 12:55

Fawad Masud

12,219
3
25
34

your approach is the last thing which I would like to do with it – Robert Jan 17 '17 at 13:05

How to encode ''+' character in url string?

3 Answers3