字符串格式化 Swift 使用\(item)的形式迚行字符串格式化: let apples = 3 let oranges = 5 let appleSummary = "I have \(apples) apples. by sollyu" let appleSummary = "I have \(apples + oranges) pieces of fruit." 数组和字典 Swift 使用[]操作符声明数组(array)和字典(dictionary): var shoppingList = ["catfi…