Swift String Substring Retrieval

Swift supports some pretty cool subscript operations, particularly in for loops. But what about String manipulation? Extensions to the rescue!

Here you can find a Swift extension that lets you specify ranges when working with String objects to obtain substrings:

    let string1 = "ABCDE"    let string2 = string1[0...3] // returns "ABCD"    let string3 = string1[1..<4] // returns "BCD"

These are valid String objects that can be used as you would any other String.

    //    //  String+CKTextManipulation.swift    //    import Foundation    extension String {        subscript (i: Int) -> Character {            return self[self.startIndex.advancedBy(i)]        }        subscript (i: Int) -> String {            return String(self[i] as Character)        }        subscript (r: Range<Int>) -> String {            let start = self.startIndex.advancedBy(r.startIndex)            let end = self.start.advancedBy(r.endIndex - r.startIndex)            return self[start..<end]        }    }