Closures

Lesson in the iOS Roadmap · Stage 17: Callbacks

Last updated 14 September 2026

What is Closures?

Closures are self-contained blocks of code that can capture and store references to values from the surrounding context. In Swift, closures are first-class types that can be passed as arguments, stored in variables, and returned from functions. They are the basis for callbacks, higher-order functions like map and filter, and completion handlers throughout the iOS SDK.

Study this in the interactive course See the whole iOS roadmap

Closures: common questions

Can I learn Closures in Hindi?

This lesson is written in English. Once you sign in, open it in the interactive course and ask the AI tutor to explain Closures in Hindi or Hinglish. The tutor answers from this lesson’s own text, so it stays on the syllabus, and it runs on your own Google, OpenAI or Anthropic key.

Is this Closures tutorial for beginners?

It is lesson 103 of 170 in the free iOS roadmap, in stage 17, Callbacks. If you are new to iOS, start from stage 1 and come back here in order; if you already know the earlier stages, this lesson stands on its own.