201521123097 the first week of Java Program Design Study summary

1. Summary of this week's study

Know the history of the Java language and the version currently in use, and what are the JDK (Java Development Kit), the JRE (Java Runtime Environment), the JVM (Java Virtual machine), Understand the implications of encapsulation, install and set up the Java development platform, write Java programs and run them using the notepad++ and Eclipse editors.

2. Written work

1. Why are Java programs running across platforms? What are the steps to execute a Java program?

Because Java has its own operating environment, it is running on the virtual machine, the virtual machine is independent of the platform;

Step: First write the source program in the notepad++ editor, then run cmd with the Javac command to compile the source program into a. class file, and then execute the Java Interpretation command to run the Java program.

2. What is the difference between a JDK?JDK,JRE,JVM?

JDK:JDK includes the Java programming language, the utility program, and the JRE.

The difference: The JDK is for development and the JRE is for running Java programs, the JVM is the operating system of the Java program, and the JDK and the JRE all contain the JVM.

3.java HelloWorld Command, what does this parameter refer to in HelloWorld? Is it a file name? What is the meaning of this command?

Hello World is the class name. The meaning of this command is to run a Java program.

What is the use of 4.path variables? What is the use of classpath variables?

The function of the path variable is to set the search path for executing the command.

The role of the CLASSPATH variable is the path to the directory that defines the classes required by the Java program.

5. What is the difference between writing a program in Java and running a program and running it with the C language, and the intermediate and target files that are generated?

intermediate files generated using Java authoring programs are . Class documents.

The C language program is written and generated during the run . cpp.

What are the 3 app versions of the 6.Java language? What is the relationship between versions?

There is a standard version of Java Standards Edition, the Enterprise version of Java Enterprises Edition and the mobile version of Java Mirco Edition.

What is the difference between a 7.Oracle jdk and an open JDK?

Oracle JDK can be used for personal research purposes, but it is prohibited for any commercial use. The Open JDK allows for commercial use.

What are the main applications of 8.Java? What are your goals and expectations in this course?

Desktop, enterprise and embedded devices and consumer electronics devices.

3. Using the code cloud to manage Java code

201521123097 the first week of Java Program Design Study summary