Image view (system and asset) in iOS Swift - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a UIImageView used for in iOS development?

UIImageView is a view that displays an image in your app's user interface. It can show images from your app assets or system symbols.

beginner

How do you load an image from your app's asset catalog into a UIImageView?

Use UIImage(named: "imageName") to create an image from your assets, then assign it to the UIImageView's image property.

beginner

What is a system image in iOS and how do you use it?

System images are icons provided by Apple through SF Symbols. Use UIImage(systemName: "symbolName") to load them into UIImageView.

intermediate

Why should you use system images (SF Symbols) instead of custom icons when possible?

System images are optimized for different sizes and weights, support dark mode automatically, and keep your app consistent with iOS design.

intermediate

How can you make sure your UIImageView adapts well to different screen sizes?

Use Auto Layout constraints to position and size UIImageView. Also, set contentMode (like .scaleAspectFit) to keep image proportions.

Which initializer loads an image from your app's asset catalog?

A UIImage(named: "imageName")

B UIImage(systemName: "imageName")

C UIImage(contentsOfFile: "imageName")

D UIImage(assetName: "imageName")

UIImage(named:) loads images from your app's asset catalog by name.

How do you load a system symbol image into a UIImageView?

A UIImage(named: "symbolName")

B UIImage(assetName: "symbolName")

C UIImage(systemSymbol: "symbolName")

D UIImage(systemName: "symbolName")

UIImage(systemName:) loads SF Symbols, which are Apple's system icons.

What contentMode should you use to keep the image's aspect ratio inside UIImageView?

A .scaleAspectFill

B .scaleAspectFit

C .scaleToFill

D .redraw

.scaleAspectFit scales the image to fit inside the view while keeping its aspect ratio.

Why are SF Symbols recommended for icons in iOS apps?

A They are only available on iOS 12 and earlier

B They are free to customize with any color

C They automatically adapt to different sizes and dark mode

D They require no code to use

SF Symbols adapt to size, weight, and dark mode automatically, ensuring consistent design.

Which property of UIImageView controls how the image fits inside the view?

A contentMode

B clipsToBounds

C image

D tintColor

contentMode defines how the image is scaled or positioned inside the UIImageView.

Explain how to display both a system image and an asset image in UIImageView.

Think about the two different UIImage initializers.

Describe why using Auto Layout and contentMode is important for UIImageView in different screen sizes.

Consider how images look on small and large devices.