I already said that variables have that name because their values can change over time, and that is often useful. However, very often you want to set a value once and never change it, and so we have an alternative to the
var keyword called
let keyword creates constants, which are values that can be set once and never again. For example:
let taylor = "swift"
If you try to change that, Xcode will refuse to run your code. It’s a form of safety: when you use constants you can no longer change something by accident.
When you write your own Swift code, you should always use
let unless you specifically want to change a value. In fact, Xcode will warn you if you use
var then don’t change the variable.
SPONSORED Instabug helps you identify and resolve severe crashes quickly. You can retrace in-app events and know exactly which line of code caused the crash along with environment details, network logs, repro steps, and the session profiler. Ask more questions or keep users up-to-date with in-app replies straight from your dashboard. Instabug takes data privacy seriously, so no one sees your data but you! See more detailed features comparison and try Instabug's crash reporting SDK for free.