Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
289 views
in Technique[技术] by (71.8m points)

ios - Remove Last Two Characters in a String

Is there a quick way to remove the last two characters in a String in Swift? I see there is a simple way to remove the last character as clearly noted here. Do you know how to remove the last two characters? Thanks!

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

update: Xcode 9 ? Swift 4 or later

String now conforms to RangeReplaceableCollection so you can use collection method dropLast straight in the String and therefore an extension it is not necessary anymore. The only difference is that it returns a Substring. If you need a String you need to initialize a new one from it:

let string = "0123456789"
let substring1 = string.dropLast(2)         // "01234567"
let substring2 = substring1.dropLast()      // "0123456"
let result = String(substring2.dropLast())  // "012345"

We can also extend LosslessStringConvertible to add trailing syntax which I think improves readability:

extension LosslessStringConvertible {
    var string: String { .init(self) }
}

Usage:

let result = substring.dropLast().string

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...