201521123119 Java programming 1th Week of study summary

1. Summary of this week's study

1. TheJava language is a multi-purpose language, a concurrency language, a class-based, object-oriented language.

2.Java is more convenient than C + +, with auxiliary input, writing speed is greatly accelerated.

3.Java differs from application domain to Java SE, Java EE and Java me three platforms, while Java SE is the foundation of each application platform.

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 running environment for Java virtual machines, virtual machines are not platform-independent.

Step: The Java program is first encoded by the encoder into a. class file, and the JVM then translates the file into a machine code and runs on the computer at the end.

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

The JDK is the Java SDK. The difference between the JDK and the JRE is that the user, the JDK for the professional developer, and the JRE for the general population. The JDK is a toolkit, and the JVM is just a virtual machine.

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 a file name. The meaning is to execute HelloWorld this file.

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

A path to the compiled file. Provides the JVM with the path to 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 runs the steps of handing the compiled code to the JVM and finally the computer executing the program. The C language program runs the steps of compiling the target file into a binary file and then matching the system function library to form an executable target file. The intermediate file formed by Java is a. class file, while the middle file of the C language is a binary file.

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

The Java language has three application versions of Java SE, Java ee, and Java me. Java SE is the basis for another two release.

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

The Open JDK is more streamlined than Oracle JDK functionality.

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

Java is mainly used in network programming, enterprise-level development and mobile phone development. I hope I can master this language and enhance my strength.

3. Using the code cloud to manage Java code

201521123119 Java programming 1th Week of study summary