Last time we mentioned agreement，But we talk about it the way an application，This lesson we take a deeper look at this class and used up almost exactly what profound esoteric protocol。
Now，We again review the shameful inheritance tree once：
Here we wrote a weapon ...... is used for attack and defense。Then，As a game，Model weapons can not just only in one place[……]
Rewriting said method，We come back to look at the inheritance tree：
This should look okay，We can create an instance of the sword，Create an instance of a pistol ......
But if I have to write it?
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var 武器 = 武器() |
So the question is：excavator……
Do not，Our problem is "weapon" in the end is what?[……]
Said so many times rewriting，This time we have to rewrite treat seriously what method。
We say，Inheritance is the equivalent of signing a contract，We inherited out of the subclass must comply with this contract，So even if you want to do something where no contract，Must comply with contract specifications，So，You override methods，It must also comply with the type of process。
We talked about the type of approach，It ()->() Such[……]
We finished the last lesson inheritance，That this lesson we will continue in-depth，What to look at inheritance tree is big move。
You and I could talk about this polymorphic pronunciation，Your first thought should be a high school biology talked of "polypeptide"；Ok，The only possibility is to pronounce the same between the two。
We say that to achieve the extraordinary significance of inherited，It greatly reduces the number of redundant lines in our code，Reducing the difficulty of maintaining the code ......[……]
Last time we specifically about the inheritance mechanism，And also designed an inheritance tree，So the question is：I'm not going to ask Excavator strong Which? I want to ask how to determine whether a class is a subclass of another class do? How do we design a class instead of a class of attributes?
Here we will use such a method to examine the relationship between the two of them：
we say，Pistol firearms --O[……]
This time we take a look at a few lessons in succession before mentioned，We had初见 OPEN In a development with a mobile phone (system) to describe inherited this thing chestnuts，I believe we have the impression。
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class CellPhone { func call() { print("Call someone!") } func powerUp () { print("Welcome!") } func powerDown() { print("Goodbye~") } func sendMessage() { print("sent a Message!") } } |
So this lesson we will learn to understand the depth of the concept of inheritance。
This is actually not difficult to understand，You see，when[……]
This lesson we try to develop a simple command-line games，To complete the experience a so-called "development process"。
This is a board game，We guess the location of enemy ships，As long as the number of hits you can send them to sink。
We give these ships the label affixed to point it ...... such a variety of sites?So，This has become a site of attack Behind his program ......。
We want players to[……]
Before we in class，Take a look at the previously mentioned "SoC" concept，We say this is called "Separation of Concerns"，I translate it as separation of duties - the different sections that focus on their part。Or a target to achieve a goal。
The goal not only to make the code more modular and easier to maintain，Also let the system run more efficiently。So，We want Object[……]
We use var to declare a variable，Congguizili like a tube placed in the experimental stage；
We give a specified variable type，Just like in the test tube labeled the；
Then put reagents must be marked on the label - otherwise could cause an explosion or poisoning。
Same，If we try to give a reservoir into a wrong data type，Then the compiler[……]