swift-switch

// switch 可以判断除整型之外的其他类型
/** switch 
 switch 可以判断除整型之外的其他类型
 `fallthrough` 关键字 表示可以继续向下执行
 */
let point = (0, 0)

switch point {
case (0, 0):
    print("orign")
    fallthrough
case (_, 0):
    print("X")
case (0, _):
    print("Y")
default:
    print("point")
}

// where 添加判断条件
let point = (1, 3)

switch point {
case let (x, y) where x == y:
    print("X == Y")
case let (x, y) where x == -y:
    print("X == Y")
case (_, _):
    print("point")
    
}

// if case 判断条件 where
let age = 19

if case 10...19 = age {
    print("age is 19")
}


if case 10...19 = age, age >= 18 {
    print("age is 19 , teenager")
}