I'm using swift in my project. I want to change a specific range of string with a character. for example I have a string "1234567890" and I want to change characters in range, location 5 and length 3 to "". the out put should be "12345***90".
I see a ways for doing this by converting string to NSString and using this function:
stringByReplacingCharactersInRange
but is there any better way? a swift way :)
There's a way to write that in Swift in one line:
let stringA = "1234567890"
let stringB = String(stringA.enumerated().map { !(5...7).contains($0) ? $1 : "*" })
let stringC = String(stringA.enumerated().compactMap { !(5...7).contains($0) ? $1 : $0 == 5 ? "*" : nil })
print(stringB) // "12345***90\n"
print(stringC) // "12345*90\n"
Just to add some explanation:
We enumarate the String so we can use the indexes to map the Characters based on their position on the String. On the closure, $0 corresponds to the offset and $1 to the Character on the iteration. It could also be written as $0.offset and $0.element, respectively.
On the second example with stringC, where it replaces with only one *, we replace the Character in position 5 with the * and the rest with nil, and the compactMap will return all of the non-nil results.
(5...7).contains($0) ? "*" : $1 compactMap { !(5...7).contains($0) ? $1 : 5 == $0 ? "*" : nil }
Maybe this?
var myString = "1234567890"
let startIndex = myString.index(myString.startIndex, offsetBy: 5)
let endIndex = myString.index(startIndex, offsetBy: 3)
myString.replaceSubrange(startIndex..<endIndex, with: "***")
print("\(myString)")
Write an extension if necessary
extension String {
mutating func replaceSubString(startAt: Int, offsetBy: Int, with newString: String) {
let startIndex = self.index(self.startIndex, offsetBy: startAt)
let endIndex = self.index(startIndex, offsetBy: offsetBy)
self.replaceSubrange(startIndex..<endIndex, with: newString)
}
}
and you use it like this:
var myString = "1234567890"
myString.replaceSubString(startAt: 5, offsetBy: 3, with: "***")
print("\(myString)")
