Any way to replace characters on Swift String?

Question

I am looking for a way to replace characters in a Swift String.

Example: \"This is my string\"

I would like to replace \" \" with \"+\" to get \

Answer 1

Here's an extension for an in-place occurrences replace method on String, that doesn't no an unnecessary copy and do everything in place:

extension String {
    mutating func replaceOccurrences(of target: Target, with replacement: Replacement, options: String.CompareOptions = [], locale: Locale? = nil) {
        var range: Range?
        repeat {
            range = self.range(of: target, options: options, range: range.map { self.index($0.lowerBound, offsetBy: replacement.count)..

(The method signature also mimics the signature of the built-in String.replacingOccurrences() method)

May be used in the following way:

var string = "this is a string"
string.replaceOccurrences(of: " ", with: "_")
print(string) // "this_is_a_string"