Completion Handlers

I’ve heard about it. I don’t know how to make one

Do something when something has been done

1. Notify the user when the download completed

Design Handler Block

Create a function that is similar to downloading an image by calling a loop. Once the download has been finished, you may notify the user.

The function above takes a parameter whose type is . You will pass .

Pass Closure Directly

3006_completion_handlers.playground

Resources

Completion Handlers in Swift with Bob