NEW! Master Swift design patterns with my latest book! >>

How to read a single character from a string

Paul Hudson       @twostraws

Swift’s strings are stored in a specific way that stops you from indexing into then easily. In fact, reading one letter from part-way through the string means starting at the beginning of the string and counting through letters until you find the one you want, so if you try reading all the characters in the string this way you could accidentally create extremely slow code.

However, if you only need to read one or two letters, here’s a simple extension on String that will help:

extension String {
    subscript(i: Int) -> String {
        return String(self[index(startIndex, offsetBy: i)])
    }
}

With that place in place, you can write myString[15] to read the 16th letter.

Available from iOS 8.0

Did this solution work for you? Please pass it on!

Other people are reading…

About the Swift Knowledge Base

This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.

Hacking with watchOS

Transfer your Swift skills to watchOS the easy way, and learn to build real-world apps in the process!

MASTER SWIFT NOW
Buy Practical iOS 12 Buy Pro Swift Buy Swift Design Patterns Buy Practical iOS 11 Buy Swift Coding Challenges Buy Server-Side Swift (Vapor Edition) Buy Server-Side Swift (Kitura Edition) Buy Hacking with macOS Buy Advanced iOS Volume One Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with Swift Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Beyond Code

Was this page useful? Let me know!

Click here to visit the Hacking with Swift store >>