start-time-end-time-elapsed-time | ios-app-dev-memo

swift

@State var startTime   : DispatchTime? = nil
@State var endTime     : DispatchTime? = nil
...
startTime = DispatchTime.now()
endTime   = DispatchTime.now()


let endTime = DispatchTime.now()
let nanosec = endTime.uptimeNanoseconds - startTime.uptimeNanoseconds
let seconds = Double(nanosec) / 1_000_000_000