20165324 Java Programming 3rd week of study summary

20165324 "Java Program Design" The 3rd week study summary textbook Learning content Summary

Here's what to learn this week:

• Programming language Ideas

1. The core of the process-oriented language is to write a block of code to solve a problem; In object-oriented language, the core content is the object, all around the object.
   2. One of the core ideas of object programming: encapsulating data and manipulating data. Through abstraction, a general concept is formed.

• Class definition: Include; class declaration and class body, in the form of:

  class 类名｛类体的内容｝//class是关键字，用来定义类。

  The purpose of a class is to abstract properties and behaviors that are common to a category of things (similar to the structure of a C language). The content of a class body consists of the declaration of a variable and the definition of a method.

• Method Definition: Contains the method header and the method body. The format is:

  方法头 {方法体的内容}//方法头由方法的类型、名称、和小括号里的参数列表所构成（与C语言中的函数相似）

• member variables and local variables: validity, the use of the keyword this, local variables must be guaranteed to have a default value, otherwise it cannot be compiled.
• UML Circles for classes: Three layers describe the main components of a class:

1. First Layer: Name layer
2. Second Layer: Variable layer
3. Layer Three: Method layer

• A construction method is a special method in a class that guarantees that the method name is consistent with the class name and has no type.
  -. Create object: Contains the declaration of the object, assigns the variable to the object. (similar to C-language constructs) assigns objects using the new operator and the constructor of the class. Such as:

  // 书本p62XiyoujiRenwu zhubajie;//声明对象zhubajie=new XiyoujiRenwu();//为对象分配变量//等价于：XiyoujiRenwu zhubajie=XiyoujiRenwu();//声明对象的同时为对象分配变量

• Combination and reuse of objects

• Instance methods and class method definitions: the instance method type is preceded by no keywords.

• Use of this: this.x the variable x that represents the current object.

• Use of the package and use of import statements

Code Hosting

PS: There is a question, I clearly did not upload the code today, why the day code has more than 1000 lines, will it be because I sometimes the local files are all deleted, and then downloaded from the code cloud caused it?

Learning progress Bar

	lines of code (new/cumulative)	Blog Volume (Add/accumulate)	Learning Time (new/cumulative)	Important Growth
Goal	3000 rows	30 Articles	400 hours
First week	200/200	1/1	15/15
Second week	300/500	1/2	12/27
Third week	1000/1500	2/4	20/47

Resources

• Java Learning Notes (8th Edition)

• Java Learning Note (8th Edition) Learning Guide

• ...

20165324 Java Programming 3rd week of study summary