行为. ruby>
Human | def ident
y | pr
"I'm a person.\n" | end
| def train_toll(age)
|
age < 12 | pr
"Reduced fare.\n"; |
| pr
"Normal fare.\n"; | end
| end
| end
nil
ruby> Human.
.identy I'm a person.
nil
ruby>
Student1<Human | def ident
y | pr
"I'm a student.\n" | end
| end
nil
ruby> Student1.
.identy I'm a student.
nil
如果我们只是想增强父类
identy 思路方法而不是完全地替代它,就可以用 super. ruby>
Student2<Human | def ident
y | super
| pr
"I'm a student too.\n" | end
| end
nil
ruby> Student2.
.identy I'm a human.
I'm a student too.
nil
super 也可以让我们向原有
思路方法传递参数.这里有时会有两种类型人... ruby>
Dishonest<Human | def train_toll(age)
| super(11) # we want a cheap fare.
| end
| end
nil
ruby> Dishonest.
.train_toll(25) Reduced fare.
nil
ruby>
Honest<Human | def train_toll(age)
| super(age) # pass the argument we were given
| end
| end
nil
ruby> Honest.
.train_toll(25) Normal fare.
nil
最新评论