201521123070 Java programming 1th Week of study summary

Summary of this week's study

1. Met three platforms Java SE, Java EE, Java ME.

2. Understand the JDK,JVM and JRE, and familiarize yourself with the operation of the JDK and download the installation.

3. Learn to use blog writing industry.

Written work

Q1. Why are Java programs running across platforms? What are the steps to execute a Java program? (please write in your own language)

Applications cannot achieve cross-platform purposes that are compiled once, and are performed everywhere. But Java is a high-level language, and when compiled,

is a bit code translated into the intermediary format, while executing the bit code, the JVM translates the bit code into a platform-dependent machine code, so Java can run across platforms.

Step 1. Download and install JDK 2. Compose Java source code (① definition class ② definition chunk ③ definition Main () method ④ compose description) 3. Run the program

Q2. What is the difference between JDK?JDK,JRE,JVM?

The JDK includes the Java programming language, the tool program, and the JRE.

The difference: The JDK itself includes the JRE,JRE, which includes the JVM. The Java program requires a JDK, just the execution of the program with the JRE, and the JVM is a Java program

The only operating system you know, the executable file is a class document.

Q3.java HelloWorld Command, what does this parameter refer to in HelloWorld?

Hello world refers to the class name.

What is the use of Q4.path variables?

Path: Set the path information for the tool in path, and the system can find the command you want to execute in path.

When the instruction does not specify the path information, the operating system will follow the path sequence set in the path variable to find out if there is a command under each path.

Q5. What is the difference between writing a program in Java and running a program and running it with the C language, and the resulting intermediate file and target file?

Java:1. Source files are compiled by the compiler into bytecode (class. class files,. java source files) 2. Bytecode is run by the Java Virtual machine interpretation

C:1. Edit the input source program co-existence disk (. C) 2. Translating the source program into a destination file (. obj) 3. Generating the target file with an executable (. exe) file

and execute the file to get the running result.

Q6. What are the different development platforms for the Java language?

Eclipse, MyEclipse, NetBeans

Q7. What is the difference between Oracle jdk and open jdk?

Oracle JDK can only be used for personal research use, prohibit commercial use, and open JDK7, so open JDK7 must delete many of the two

There is a conflicting program code between the authorizations.

Experiment summary and code submission record on code cloud

3.1 Commit History of the week

3.2 Experimental Summary

1. The class name and document name are the same;

2. The code cloud really is very difficult to engage in!

201521123070 Java programming 1th Week of study summary