CODEWITHSUNDEEP
stringswiftreplace
sloeberGJ
sloeberGJ

Reputation: 385

Replace sequence of spaces in string with a single character in swift

I want to replace a series of spaces from a string with an underscore. For example

"This       is     a string with a lot of spaces!"

should become

"This_is_a_string_with_a_lot_of_spaces!"

How to do this?

Upvotes: 3

Views: 2341

Answers (4)

user887210
user887210

Reputation:

Alternative non-regex, pure Swift (no bridging to NSString) solution:

let spaced = "This       is     a string with a lot of spaces!"

let under = spaced.characters.split(" ", allowEmptySlices: false).map(String.init).joinWithSeparator("_")

Alternate, alternate version that doesn't remove leading and trailing spaces when converting. Slightly obfuscated for brevity... ;-)

let reduced = String(spaced.characters.reduce([Character]()) { let n = $1 == " " ? "_" : $1; var o = $0; o.append(n); guard let e = $0.last else { return o }; return e == "_" && n == "_" ? $0 : o })

There's probably a more clever solution involving flatMap() but I'll leave it to someone more clever than I!

Upvotes: 1

brandonscript
brandonscript

Reputation: 72905

You can use a simple regular expression replacement to do this:

let myString = "😀😬 😁😀 😬 😁😀 😬 😁"
if let regex = try? NSRegularExpression(pattern: "\\s+", options: []) {
    let replacement = regex.stringByReplacingMatchesInString(myString, options: .WithTransparentBounds, range: NSMakeRange(0, (myString as NSString).length), withTemplate: "_")
    print(replacement)
    // "😀😬_😁😀_😬_😁😀_😬_😁"
}

Upvotes: 3

Martin R
Martin R

Reputation: 539795

@remus suggestion can be simplified (and made Unicode/Emoji/Flag-safe) as

let myString = "  This       is     a string with a lot of spaces! 😀😬    🇨🇦  🇨🇰  "
let replacement = myString.stringByReplacingOccurrencesOfString("\\s+", withString: "_", options: .RegularExpressionSearch)
print(replacement)
// _This_is_a_string_with_a_lot_of_spaces!_😀😬_🇨🇦_🇨🇰_

Upvotes: 6

dfrib
dfrib

Reputation: 73186

Alternative non-regex solution:

let foo = "This       is     a string with a lot of spaces!"
let bar = foo
    .componentsSeparatedByString(" ")
    .filter { !$0.isEmpty }
    .joinWithSeparator("_")

print(bar) /* This_is_a_string_with_a_lot_of_spaces! */

Works also for unicode characters (thanks @MartinR for this beautiful example)

let foo = "😀😬 😁😀   😬 😁😀 😬 😁"

// ...

/* 😀😬_😁😀_😬_😁😀_😬_😁 */

Upvotes: 12

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