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1. CaseIterable

enum City {
case new_york
case bei_jing
case vancouver
let cities: [City] = [.new_york, .bei_jing, .vancouver…

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struct Uppercased {
var wrappedValue: String {
didSet { wrappedValue = wrappedValue.uppercased() }
init(wrappedValue: String) {
self.wrappedValue = wrappedValue.uppercased()

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XCTAssert(expression: Bool)

func testAssertion() {
let number = 2
XCTAssert(number > 1) // success
XCTAssert(number == 1) // failure

XCTAssertTrue(expression: Bool)

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Case 1

  1. If the user is suspicious, we will sign him/her out;
  2. If the user is unauthorized, we will sign him/her in, retrieve the location and the weather;
  3. If the user is authorized, we will retrieve the location…

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What’s a “God Class”?

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What is a variable?

How to declare a variable?

var name = "Steve"
var age: Int = 35
var height: Double = 8.9
var isTall: Bool = {
return height > 7

Dylan Chen

iOS Engineer, interested in Flutter. Nothing is better than solving complex problems with clean, elegant code. I have a passion for design and programming.

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