Program, things in real life a map in the computer.
Mirror. Painting. Camera.
The word from the program live, usually refers to the completion of the process and an established way certain things.
Program can be described as the process of a series of actions to perform.
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4: Computer Languages
Computer languages (Computer Language) is a language for communication between people and computers, it is mainly composed of a number of instructions, the instructions including digital content, and grammar symbols programmers can command the computer through a variety of these instructions work.
Computer language classification
(1) machine language
(2) assembly language
(3) high-level language
: The computer can recognize only the language machine language.
Machine language is encoded by the binary 0 and 1. It is not easy to recognize and remember.
Assembly language identifier using the abbreviation, easy to recognize and remember. Student --- stu; list --- ls
Identifier: In order to distinguish different things given number (name)
High-level language
using nearly natural human language programming to further simplify the process of writing programs, so is the choice for most high-level language programmer.
the then ---- ---- IF
^^^ *** --- ((()))
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5: keyboard function keys and shortcut keys
A: keyboard function keys
* A: the Tab
* B: the Shift
* C: the Ctrl
* D: the Alt
* E: Space
* F: the Enter
* G: the Window
* H: arrow keys
* i: PrtSc (PrintScreen) Screenshots
* B: Keyboard shortcuts
* a: Ctrl + A Select
* b: Ctrl + C Copy
* c: Ctrl + V paste
* d: Ctrl + X Cut
* e: Ctrl + Z Undo
* f: Ctrl + S Save
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6: how to open a DOS console
how to open a DOS console?
* C: win + r - cmd - Enter
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7: common DOS commands
* A: d: Enter switch letter
* B: dir (directory): List files as well as files in the current directory folder
* C: cd (change directory) to change the specified directory (into the specified directory)
* D: cd ..: return to the parent directory
* E: cd \: return to the root directory
* F: cls: (clear screen ) clear screen
* G: exit: exit the dos command line (
* Md (make directory): Create a directory
* rd (remove directory): delete the directory
* del (delete): delete the file,
rd + / s folder name (asking whether to delete)
RD + / + q / S folder name (delete)
yes
NO
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8: Java Language Overview
* A: Java language development history
* James Gosling (James Gosling) 1977 was awarded a bachelor's degree in Computer Science, University of Calgary, Canada, in 1983 received a doctorate in computer science from Carnegie Mellon University, IBM after graduation to work, the design of the first generation of IBM workstations NeWS system, but neglected. Later, go to the Sun, in 1990, cooperation "Green Plan" and Patrick, Naughton and Mike Sheridan and others, and later developed a language called "Oak", later renamed Java.
* SUN (Stanford University Network, Stanford University Networks)
* B: the Java language version
C: Java language platform
* J2SE (Java 2 Platform Standard Edition ) Standard Edition
* is a solution for the development of ordinary desktop and business applications provide the technical system is the basis for the other two, you can do some develop desktop applications
* J2EE (Java 2 Platform Enterprise Edition ) Enterprise Edition
* for developing applications in enterprise environments to provide a set of solutions, the technology system included techniques such as Servlet, Jsp, etc., aimed at Web application development
* C : Java language features
* simplicity
* explanatory
* object-oriented
* High performance
* distributed processing
* multi-threaded
* robustness
* dynamic
neutral structure *
* security
* open source
* cross-platform
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9: a: What is cross-platform
* B: the principle of cross-platform Java language
* as long as the operating system to run on java application, install a Java virtual machine (JVM Java Virtual Machine) can be. By the JVM is responsible for running Java programs in the system.
* C: Java language, cross-platform graphical
! * Write once, run anywhere (a compile, run everywhere)
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10: Overview of the JRE and JDK
* A: What is the JRE
* includes the Java Virtual Machine (JVM Java Virtual Machine) and the required core class libraries and other Java programs,
If you want to develop a good run Java programs, the computer can only be installed JRE.
* JRE: JVM + class library.
* B: What is the JDK
the JDK (java Development Kit java development kit
* JDK is available to Java developers, which contains the java development tools, including the JRE so installed JDK, do not have a separate installation of JRE. a.
* where development tools: compiler tools (javac.exe) packaging tool (jar.exe), etc.
* JDK:. JRE + JAVA development tools
* C: Why JDK contains a JRE
* Why does the JDK includes a JRE ?
* End of program development, we need to run it and see the effect.
* D: the role of JDK, JRE, JVM and relations
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11: JDK download and installation
* A: JDK download
* a: the official website http://www.oracle.com
* B: JDK installation
Download and install Reference:
https://blog.csdn.net/u012934325/article/details/73441617/
* A: fool installation
* Double-click the installer, and then all the way next to (but not recommended)
* b: Recommended installation way
* the installation path do not have Chinese or special characters such as spaces.
* All the best and the development of related software installation directory unity.
* Example: my JDK installation path
* D: \ Develop \ the Java \ jdk1.7.0_72
* When prompted to install the JRE, you can choose not to install. Recommendations or installed.
* C: demo installation process
* can first create a file folder on disk d Develop
* C: Verify that the installation was successful
* a: through DOS commands to switch to the bin directory of JDK installation.
* D: \ develop \ Java \ jdk1.7.0_72 \ bin
* B: javac and then separately enter java, if something normal display, indicating successful installation
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12: JDK installation directory path to understand
bin directory: the directory used to store a number of executable programs.
* If javac.exe (java compiler), java.exe (java run the tool), jar.exe (Packaging Tool) and * javadoc.exe (document generation tool) and so on.
db directory: db directory is a small database.
jre directory: "jre" is an abbreviation for the Java Runtime Environment, which means Java runtime environment. This directory is the root directory of the Java Runtime Environment, which includes the Java virtual machine, runtime class package, Java application launcher and a bin directory, but does not include a development environment development tool.
Contents include: JDK is due by C and C ++ implementation, so when you start the need to introduce some of the C language header files, the directory is used to store these header files.
lib directory: lib library is an abbreviation, meaning Java class libraries or library file, the archive file is to develop tools to use.
src.zip file: src.zip for the src folder of file compression,
src placed in the JDK core classes of the source code, you can view the source code for the Java Foundation Classes through the file.
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13: View version information:
the Java - Version United States [vɜrʒn]
java version " 1.8.0_191"
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14: Java development tools
* A: notepad (Microsoft operating system comes)
* B: Editplus / Notepad ++
* C: the Eclipse
* D: MyEclipse
* basic classes: first, notepad, and then Editplus, then Eclipse.
* Employment Class: MyEclipse and Eclipse are used.
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15: Eclipse Download