Strings mutating and non mutating methods

[mtsrodrigues (Mateus Rodrigues)]

Is there a particular reason why appending and append methods exist but there is no replaceCharacters alongside replacingCharacters? There is also others mutating methods that don't have a non mutating one that would be useful in case you need to chain different transformations.

[cukr]

That's because replacingCharacters isn't a String method, it's a NSString method that shows up when you import Foundation