First knowledge of java-2018-1-9

Today is the first day of the final exam, is also beginning to touch the first day of Java, not to review, then to learn something new!!

Three major platforms for Java

1. Java SE

Divided into four parts: JVM (Virtual machine), JRE (running environment), JDK (SDK), Java

2. Java EE

3. Java ME---(less used)

Java Development Environment Configuration

Notepad/notepad/ediplus/ultreadit

Eclipse/myeclipse

JCreator

Betbeans

IntelliJ idea

Java commands

Note: The naming of classes and constants in Java is capitalized, and the class name matches the file name

Java Execution commands

Javac Compile command: Java compilation

Note: 1. Documentation notes:/** */, two *, usually plus copyright notice 2. Multiline Comment:/* * */one * 3. Single-line Comment://

First attempt: (note://string,system first letter to capitalize)

public class Myfirst {
public static void Main (string[] args) {
System.out.println ("My first java!!");
}
}

First knowledge of java-2018-1-9