Swift version: 5.6
Swift lets you create both variables and constants as ways to reference your data, but there's a strong push (even Xcode warnings!) if you create things as variables then never change them. To make a constant, use let
like this:
let x = 10
To make a variable, use var
like this:
var y = 20
The reason Swift strongly encourages you to use constants wherever possible is because it's safer: if you say "this value will never change," then Swift will refuse to let you change it even by accident. It also opens the possibility of compiler optimizations if the system knows certain data will not change.
SPONSORED Proxyman: A high-performance, native macOS app for developers to easily capture, inspect, and manipulate HTTP/HTTPS traffic. The ultimate tool for debugging network traffic, supporting both iOS and Android simulators and physical devices.
Sponsor Hacking with Swift and reach the world's largest Swift community!
Available from iOS 7 – see Hacking with Swift tutorial 1
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
Link copied to your pasteboard.