if ([person.name isEqualToString:@"Matt Galloway"]) {
 NSLog(@"Author of an interesting Swift article");
} else if ([person.name isEqualToString:@"Ray Wenderlich"]) {
 NSLog(@"Has a great website");
} else if ([person.name isEqualToString:@"Tim Cook"]) {
 NSLog(@"CEO of Apple Inc.");
} else {
 NSLog(@"Someone else);
}

switch person.name {
 case "Matt Galloway":
 println("Author of an interesting Swift article")
 case "Ray Wenderlich":
 println("Has a great website")
 case "Tim Cook":
 println("CEO of Apple Inc.")
 default:
 println("Someone else")
}

let vegetable = "red pepper"
switch vegetable{
 case "celery":
  let vegetableComment = "Add some raisins and make ants on a log."
 case "cucumber","watercress":
  let vegetableComment = "That would make a good tea sandwich."

 
 //switch支持所有类型的数据，以及多种比较运算——没有限制为必须是整数，也没有限制为必须测试相等(tests for equality 真的是这样翻译的吗？)
 case let x where x.hasSuffix("pepper"):
  let vagetableComment = "Is it a spicy \(x)?"

 //switch语句要求必须覆盖所有的可能，否则报错'switch must be exhaustive, consider adding a default cla'
 default:
  print("不能没有default")
}

switch i {
case 0, 1, 2:
 println("Small")
case 3...7:
 println("Medium")
case 8..10:
 println("Large")
case _ where i % 2 == 0:
 println("Even")
case _ where i % 2 == 1:
 println("Odd")
default:
 break
}