@UIApplicationMain AppDelegate.swift

Question

In AppDelegate.swift file, I see a line of code at the very top, just below an import keyword. It says "@UIApplicationMain". What does that line of code do? What does the"@" at the beginning mean?

Swift

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ShinehahGnolaum

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Answer 1

In AppDelegate.swift file, I see a line of code at the very top, just below an import keyword. It says "@UIApplicationMain". What does that line of code do?

It indicates that this class should be treated as the app delegate for a UIKit based application. If you leave it out then you have to add a

main.swift

file that calls the

UIApplicationMain

function. This is unnecessary boilerplate, so Swift has a nice shortcut to avoid it.

What does the"@" at the beginning mean?

The

character introduces a Swift attribute, which modifies the following class declaration.

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@UIApplicationMain AppDelegate.swift

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