Abstract: Summary of Class Notes 1 Theory 2 Basic Logic if eise for while 3: 1: Java Language Programming Language Natural Language Computer Language 2: Programming Language Classification Based on Data Type Strongly Typed Programming Language Weakly Typed Programming Language: eg C language
Class notes 4.23
Summary
1 Theory
2 Basic logic if eise for while
3:
1: java language programming language natural language
计算机语言
2: Programming language classification
根据数据类型 强类型编程语言 弱类型编程语言 :eg C语言
根据执行方式 编译执行---Java源文件---javac编程---java执行 Java----class
解释执行---shell脚本---.sh源文件---更改x权限---执行 C----a.out
3. Computer language classification compilation: Java, C, C
解释: shell、 Python、PHP
Comments : java is a language where compilation and interpretation coexist
C语言是纯正编译语言
4. Composition of programming language
×词法和语法规则 *编译器和解释器 ×开发中常用包 API ---工作当中经常用到 --application platform interface应用平台网络接口 ×集成环境IDE ---Integrated Development Environment
Note: JDK is also a simple IDE
Note: It is best to install software and apps 1~2 versions lower than the latest version
Note: The teacher recommends a book: "Self-Study Programming Language" //If you are interested in the language
Classification of Java language---- According to different applicable fields
----JavaSE 新(J2SE 旧)--必学的-- java 2 platform standard edition ----JavaME (J2ME)----用的比较少-- ----JavaEE (J2EE) ----大行其道--- JavaWeb //Java工程师----JavaEE----后台开发的
5. JavaSE(14day) ---Android API
---JavaEE-----Java后台开发工程师 ---BigData----大数据开发工程师(4month)
6.---JDK---//Development tool lib ---javac == ===Java Development kit & Java Development Kit
----JRE---// lib =====Java Runtime Environment =====Java Runtime Environment
----JVM---- Virtual machine//JRE and JVM are bundled together
//Learn more about java later "JVM Virtual Machine Principles"
7. Environment variables
---path-----classpath------JAVA_HOME
---Path system environment variable-----javac can be used everywhere
---clasPath----.java-----.class-----.java file storage directory
================ ==
export Path = $ Path
export classport
Path /tools/jdk/8/bin
Java_HOME tools/jdk/8 /---------IDE development tools//Note: Looking for Java development tools
8. Naming rules for indicators? ==========The class name is exactly the same as the file name
9. Data type
----基本数据类型-----Java默认存在 //数据类型 == 变量名== 初始值 -----引用数据类型 ---java存在的 -----Scanner -----自定义类 //类名 == 变量名==对象的初始值
//"Reference data type"-----from hadoop, project The beginning will involve reference data types
//Learn about the data types of C language
// -----Byte----Unit byte
-----byte----java整型变量的byte类型 -----bit-----比特 1010
//Countermeasures against fuzzy concepts======List similar word concepts for "comparison" to strengthen memory====A recommended learning technique
How to listen to the class? How to practice? How? Efficiency in listening to lectures?
**'Write', 'Remember', 'Ask'==== "Ask" is very important
**Review and sort out in the afternoon
**Exercise
**Think =========Horizontal penetration========
10. Data conversion
Small---Large========No accuracy will be lost
Large---Small========Accuracy will be lost
"Forced type conversion"---Read the courseware in advance
11. Data conversion of reference types
--- The numbers must be correct to force conversion---
==================================== ============================
public static -----void----- --- -main (String[] args)----
/**
Custom method steps:
*/
? ????
Return value type: There is a return value (return value is required) ----- Select ==== basic data type and reference data type
没有返回值 ------void
12. Homework 50 this week Job code
Related recommendations:
Summary of the four and eight basic data types of Java
Java language cross-platform principle-JAVA Elementary introductory video tutorial
The above is the detailed content of Java basic theory and programming language classification. For more information, please follow other related articles on the PHP Chinese website!