October 2020
Beginner to intermediate
499 pages
9h 13m
Chinese
Content preview from Raku学习手册
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250
｜
第
12
章
练习
12.4
为
Hamadryas
蝴蝶的界（
kingdom
）、门（
phylum
）、纲（
class
）、目（
order
）、
科（
family
）和属（
genus
）创建类。门继承界，纲继承门，依此类推。每个类
要明确它在这个继承体系中的位置：
class Nymphalidae is Lepidoptera { }
在
Hamadryas
中定义一个
.full-name
方法，把所有级别连想来。
属
Hamadryas
属于
Animalia
界，
Arthropodia
门，
Insecta
纲，
Lepidoptera
目，
Nymphalidae
科。
12.5.1
检查继承
你已经看到
.^mro
可以得到类的一个
List
。
.isa
方法返回
True
或
False
来指示你
指定的类型是否在这个
List
中。可以用一个类型对象作为参数（
Str
）测试它是一
个类型还是一个对象：
put Int.isa: 'Cool'; # True
put Int.isa: Cool; # True
put Butterfly.isa: Insect; # True;
put Butterfly.isa: Int # False;
my $butterfly-object = Butterfly.new;
put $butterfly.isa: Insect; # True
智能匹配可以做同样的工作，这也是只提供一个类型时
when
检查的内容：
if Butterfly ~~ Insect {
put "Butterfly is an Insect"; ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.