Swift - iOS: Remove spaces inside a String before or after any special character

Question

I have to do validation to check user entered answer to an application. I want to remove spaces (if any) left or before for bellow special characters.

/

,

:

;

-

.

So the final output should be like this.

Ex:

Correct answer => a/b

Answers need to accept => ' a/b ', 'a/ b', 'a /b', 'a/ b ', 'a/b '

I can do this using replacingOccurrences function by replacing all possible values. Is there any better solution for this?

Ex: ' apple / orange', 'apple /orange ', 'apple / orange ', ' apple / orange', => These values need to convert to 'apple/orange' — sameera, Mar 22 '19 at 04:30
Possible duplicate of [How to remove whitespaces in strings in Swift?](https://stackoverflow.com/questions/28548908/how-to-remove-whitespaces-in-strings-in-swift) — Rakesha Shastri, Mar 22 '19 at 04:38
@RakeshaShastri I don't want to trim the string. I need to remove spaces on or before above mentioned special characters (Inside a string). — sameera, Mar 22 '19 at 04:41
What happens if there is more whitespaces than one? `a_/_____b` — Robert Dresler, Mar 25 '19 at 06:18

Quoc Nguyen · Accepted Answer · 2019-03-22T08:57:06.160

2

You can using regular expression for replace the string with format [ ]+{special_char} and {special_char}[ ]+.

Edit

Update "." to "\\."

Thanks ielyamani

For example

func acceptedAnswer(of answer: String) -> String {
    let specialChars = ["/", ":", ",", ";", "-", "\\."]
    var newAnswer = answer.trimmingCharacters(in: .whitespacesAndNewlines)
    for specialChar in specialChars {
        let beforeCharRegex = "[ ]+" + specialChar
        let afterCharRegex = specialChar + "[ ]+"
        newAnswer = newAnswer.replacingOccurrences(of: beforeCharRegex, with: specialChar, options: .regularExpression, range: nil)
        newAnswer = newAnswer.replacingOccurrences(of: afterCharRegex, with: specialChar, options: .regularExpression, range: nil)
    }
    return newAnswer
}

print(acceptedAnswer(of: " apple /   orange     : banana    "))
// apple/orange:banana

edited Mar 22 '19 at 08:57

answered Mar 22 '19 at 04:51

Quoc Nguyen

2,839
6
23
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1

I checked your answer. But if there any space between words this solution will not work. Ex: " Apple / Green orange" => Answer should be "Apple/Green orange" - But in your solution answer will be "Apple/Orance.anana" – sameera Mar 22 '19 at 05:46
@sameera Use `"\\."` instead of `"."` – ielyamani Mar 22 '19 at 05:46
@sameera Sorry about it, updated answer with suggestion from ielyamani – Quoc Nguyen Mar 22 '19 at 08:58

Amir Khan · Answer 2 · 2019-03-22T08:52:33.780

0

Remove before and after space of Special character using Range -

    let specialChars = ["/",":", ",", ";", "-", "."]
    let aString = " AB / CD EF ; G : H , MN O - P"
    var trimmedString = aString.trimmingCharacters(in: .whitespacesAndNewlines)

    for specialChar in specialChars {

        if let beforeSpacerange = trimmedString.range(of: " \(specialChar)") {
            trimmedString.replaceSubrange(beforeSpacerange, with: specialChar)
        }
        if let afterSpacerange = trimmedString.range(of: "\(specialChar) ") {
            trimmedString.replaceSubrange(afterSpacerange, with: specialChar)
        }

    }

    debugPrint(trimmedString)

Hope it will help you. Let me know if you are still having any issue.

Happy coding.

edited Mar 22 '19 at 08:52

answered Mar 22 '19 at 04:51

Amir Khan

1,318
1
14
39

I checked your answer, But I don't need to replace all spaces inside the string. I need to replace spaces which are after or before above special characters. Ex: " Apple / Orance Banana" => "Apple/Orance Banana" – sameera Mar 22 '19 at 05:41
You need to read the question again since you have clearly misunderstood it. Not all spaces should be removed, please improve your answer. – Joakim Danielson Mar 22 '19 at 06:53
My bad I got that wrong. @JoakimDanielson I've updated my answer. Please check. – Amir Khan Mar 22 '19 at 08:53
2

This answer is more optimised than accepted answer. Cheers! – Manish Mar 22 '19 at 11:14

Robert Dresler · Answer 3 · 2019-03-22T06:35:36.390

You can use replacingOccurrences which would replace your symbol with whitespaces with just this symbol. For this purpose you can use recursive method

func removed(in text: String) -> String {
    let symbols = ["/", ",", ":", ";", "-", "."]
    var newText = text
    symbols.forEach { newText = replaced(in: newText, for: $0) }
    return newText
}

func replaced(in text: String, for symbol: String) -> String {
    var newText = text
    let left = " \(symbol)"
    newText = newText.replacingOccurrences(of: left, with: symbol)
    let right = "\(symbol) "
    newText = newText.replacingOccurrences(of: right, with: symbol)
    return newText != text ? replaced(in: newText, for: symbol) : newText
}

Usage:

let string = "Apple / Orange Swift    .   ObjC Moon  : Sun USA - UK"
print(removed(in: string))

Apple/Orange Swift.ObjC Moon:Sun USA-UK

Swift - iOS: Remove spaces inside a String before or after any special character

3 Answers3