Использование Mixin для добавления общего поведения между несвязанными объектами
As you have seen, behavior is shared through inheritance. However, there are cases when inheritance is not the best solution. Inheritance does not work well for unrelated objects like Bird
and Airplane
. They can both fly, but a Bird
is not a type of Airplane
and vice versa.
For unrelated objects, it's better to use mixins
. A mixin
allows other objects to use a collection of functions.
let flyMixin = function(obj) {
obj.fly = function() {
console.log("Flying, wooosh!");
}
};
The flyMixin
takes any object and gives it the fly
method.
let bird = {
name: "Donald",
numLegs: 2
};
let plane = {
model: "777",
numPassengers: 524
};
flyMixin(bird);
flyMixin(plane);
Here bird
and plane
are passed into flyMixin
, which then assigns the fly
function to each object. Now bird
and plane
can both fly:
bird.fly(); // prints "Flying, wooosh!"
plane.fly(); // prints "Flying, wooosh!"
Note how the mixin
allows for the same fly
method to be reused by unrelated objects bird
and plane
.
Create a mixin
named glideMixin
that defines a method named glide
. Then use the glideMixin
to give both bird
and boat
the ability to glide.