Finish the 1th day of it 18 Palm Java Foundation Course:

Learning Goals:

Introduction, role, scope of Java Fundamentals

Learning methods:

Watch videos, notes, hands-on, do homework

Learning content:

Java-related content:

1, C + + and Java are object-oriented programming

2. Java Foundation:

b/S: browser (browser)/server (WAB server)

C/S: Client/server (Database server)

Ria:rich Internet application (Internet use)

W/S: Wab/service (Communication between heterogeneous systems, which can be coordinated across platforms and across language systems)

3, Java features: can be executed on any operating system, once compiled, everywhere execution. The reason is because the sandbox "sandbox" is also known as the virtual machine JVM, so you can cross-platform , Big Data later on the JVM's various parameters of debugging optimization.

4, so big data mainly solves two questions: storage and operation

Java Authoring Note:

1. Display extension

2, the class name can not write Chinese characters, the first word note some uppercase. Columns such as: Class Demo {}

3, {} This is the meaning of the class

4, need to add a law in the class (equivalent to the entry point): public static void Main (String [] args) {}

5, Java programming in the most used sentence: System.out.println("HelloWorld");

To write the Java program order:

1. Preparation of documentation; (Demo.java)

2. Compile the Java source file Compile command: Javac Demo.java//run under the source file path, compile and produce a Demo.class file, which is the program to run next.

3. Run Java program run format: Java Demo (case sensitive)

First day Homework:

1. The difference between JDK and JRE:

The JRE is the Java Runtime Environment, the core library class. Java runs on the JVM virtual machine and the core class library.

The JDK is a developer package that installs the JDK without installing the JRE.

2. The role of path and CLASSPATH environment variables

Path is the order in which the system searches for file paths

Classpath is the order in which Java executables are found , because Javac compiles a text file and generates a file with the suffix class. So the directory where the class file will run is defined in the variable.

3. Write HelloWorld program independently

Class Demo {

public static void Main (String [] args) {

System.out.println ("HelloWorld");

}

}

Problems encountered:

Questions that need help

This article from "Mixiaoqi" blog, declined reprint!

Finish the 1th day of it 18 Palm Java Foundation Course: