What’s the difference between a function and a closure?
Swift version: 5.2
Closures and functions are very similar in Swift, but there are some subtle differences. When you’re learning, it’s easiest to think of a closure as being a function that doesn’t have a name of its own, and captures any values from its environment.
Nested functions – functions inside other functions – also capture values from their environment, but they have a name. As for global functions – functions that aren’t inside another function or type – they are also like closures, except they have a name and don’t capture values from their environment. Like I said, the differences are subtle!
Helpfully, Swift completely blurs the lines between functions, methods, operators, and closures, allowing us to use them interchangeably as long as they accept and return the correct types of data.
SPONSORED Check out Stream's cross-platform open source chat SDK on GitHub! Write once and deploy your app with fully featured chat UI on iOS and macOS.
Sponsor Hacking with Swift and reach the world's largest Swift community!
Available from iOS 8.0
Similar solutions…
- What’s the difference between a function and a method?
- What’s the difference between @ObservedObject, @State, and @EnvironmentObject?
- What’s the difference between frame and bounds?
- What’s the difference between a static variable and a class variable?
- What's the difference between UIWebView and WKWebView?
About the Swift Knowledge Base
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
