I have a string:
myString = "mystring"
I would simply like to get the first 5 characters
which is the easiest way to do that in Swift?
- 2possible duplicate stackoverflow.com/questions/24044851/…Vkt0r– Vkt0r2015-08-24 21:38:10 +00:00Commented Aug 24, 2015 at 21:38
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3 Answers
Correct answer from Choppin, but if you want to do it in the pure swift way (without casting to NS String :
myString = myString.substringToIndex(advance(myString.startIndex, 5)) 
5 Comments
Daniele B
it's crazy how very little intuitive this is in Swift
Glenn
yep, I have to google it again and again in each project because I keep forgetting it
Abizern
It may seem odd, but there are good reasons for it. For example stackoverflow.com/questions/24880604/…
Glenn
great Addition Abizern!
winterized
Not working anymore in Swift 3, but there is a working extension here: stackoverflow.com/questions/24044851/…
let substring: String = (myString as NSString).substringToIndex(5) 
Comments
Use these extensions:
Swift 2.3
extension String { func substringFromIndex(index: Int) -> String { if (index < 0 || index > self.characters.count) { print("index \(index) out of bounds") return "" } return self.substringFromIndex(self.startIndex.advancedBy(index)) } func substringToIndex(index: Int) -> String { if (index < 0 || index > self.characters.count) { print("index \(index) out of bounds") return "" } return self.substringToIndex(self.startIndex.advancedBy(index)) } func substringWithRange(start: Int, end: Int) -> String { if (start < 0 || start > self.characters.count) { print("start index \(start) out of bounds") return "" } else if end < 0 || end > self.characters.count { print("end index \(end) out of bounds") return "" } let range = Range(start: self.startIndex.advancedBy(start), end: self.startIndex.advancedBy(end)) return self.substringWithRange(range) } func substringWithRange(start: Int, location: Int) -> String { if (start < 0 || start > self.characters.count) { print("start index \(start) out of bounds") return "" } else if location < 0 || start + location > self.characters.count { print("end index \(start + location) out of bounds") return "" } let range = Range(start: self.startIndex.advancedBy(start), end: self.startIndex.advancedBy(start + location)) return self.substringWithRange(range) } } Swift 3
extension String { func substring(from index: Int) -> String { if (index < 0 || index > self.characters.count) { print("index \(index) out of bounds") return "" } return self.substring(from: self.characters.index(self.startIndex, offsetBy: index)) } func substring(to index: Int) -> String { if (index < 0 || index > self.characters.count) { print("index \(index) out of bounds") return "" } return self.substring(to: self.characters.index(self.startIndex, offsetBy: index)) } func substring(start: Int, end: Int) -> String { if (start < 0 || start > self.characters.count) { print("start index \(start) out of bounds") return "" } else if end < 0 || end > self.characters.count { print("end index \(end) out of bounds") return "" } let startIndex = self.characters.index(self.startIndex, offsetBy: start) let endIndex = self.characters.index(self.startIndex, offsetBy: end) let range = startIndex..<endIndex return self.substring(with: range) } func substring(start: Int, location: Int) -> String { if (start < 0 || start > self.characters.count) { print("start index \(start) out of bounds") return "" } else if location < 0 || start + location > self.characters.count { print("end index \(start + location) out of bounds") return "" } let startIndex = self.characters.index(self.startIndex, offsetBy: start) let endIndex = self.characters.index(self.startIndex, offsetBy: start + location) let range = startIndex..<endIndex return self.substring(with: range) } } Usage:
let myString = "mystring" let substring = myString.substringToIndex(5) 