201521123087 Java programming 1th Week of study summary

1. Learning Summary

Preliminary understanding of object-facing programming ideas

Learn to install JDK and set Java_home,path,classpath environment variables

Simple understanding of Java

2. Written work

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

(1) Java is compiled into a code document, and then by the target platform JVM to translate the bit code to fit the platform's machine code, so as long as any platform to install the exclusive JVM of the platform, you can let the Java program can run on any platform.
(2) write the source code, save the file suffix is. java, open cmd, in the source code on the hard disk input Javac file name (. java), if it is correct, you can continue to enter Java file name (no suffix), execute the file.

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

JDK is the Java language Software Development kit;

The JDK is the Java development environment, the JVM is the virtual machine, the JRE is the Java execution environment;

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

HelloWorld is the class name and is the name of the class.

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

Path is a route variable, in order for the operating system to find the specified tool program;

The CLASSPATH variable is intended to allow the Java execution environment to find the developed Java program, the. class file.

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?

Java writes a program that needs to be written in a document and compiled through the JDK. C language has a dedicated set of programming tools, directly to write, compile, etc.;

C language Intermediate file is obj, generating file is C, the target file is exe;

Java writes the intermediate file as. java, which generates a. class file and A. jar for the target file.

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

Eclipse,netbeans,idea.

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

Oracle JDK is used for personal research, Oracle JDK is published on the basis of OPENJDK, and a few original codes are replaced. Oracle JDK is more complete than open JDK functionality.

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

Should be used to develop a variety of apps. The goal is not to hang, the results of the ideal point. I heard that senior Java engineers pay very high, look forward to!!!

3. Using the code cloud to manage Java code

4. Experimental summary

sentence Mastery is not proficient, need a number of exercises, alt+/this technique is very convenient, to be used.

201521123087 Java programming 1th Week of study summary