Day Eight

The Goal

Today is day 8 of learning Swift. I’ve started book four of the documentation “Advanced patterns” here we cover subscripts, inheritance, initialization and deinitialization, optional chaining, error handling and concurrecny. Along with this continue with the L9 of the Stanford youtube video.

Notes:

• Try use aspectRatio to best handle dynamic screens
• Text can show numbers directly by passing them in like: Text(0.4, format: .number/.percent)
• To unwrap a variable in an if statement we can do

if let endTime {

}

That is the same as doing

if let endTime = endTime {

}

• We can build timers using the TimeDataSource which will keep counting. An example of this is below. This increase the count from the current date

Text(TimeDataSource<Date>.currentDate, format: .offset(to: startTime, allowedFields: [.minute, .second]))

• You can use .flexibleSystemFont() to build fonts that can scale.
• some is greatly preferred than any

Important protocols

• Equatable - makes == work;
• Hashable - For when someone wants to be able to look your stuff up
• Identifiable - used by SwiftUI to match your model up with specific views