/*
final class temp {
var name :String{
return "张三"
}
}
class temp2:temp{
override var name :String{
return "李四"
}
}
*/
/*
struct rectangle{
var l :Double
var b :Double
init(){
l = 6
b = 12
}
}
let a = rectangle()
//let a = rectangle(l:6,b:12)
print(a.l*a.b)
*/