The use of Eclipse and the identifiers and keywords of Java programs

Use of Eclipse

(1) Creating a Java Project

Select the file/new/Java Project command, enter the project name in the New Java Project dialog box that pops up, then click Next, and finally click Finish.

(2) Creating a Java class file

Select the file/New/Class command, enter a name and select the public static void main (string[] args) check box, and finally click Finish.

(3) Writing Java code

Enter "System.out.println ();" In {}, then enter the text you want to express in (), note that you want to add "" to both sides of the text, and click Run.

You can also enter sysout and then use alt+/quick completion.

PS: If the input is "print" instead of "println", its output will not be automatically branch.

Alternatively, right-click on the current line number to set a breakpoint or cancel the breakpoint, which will let the program stop at this point and continue running if the second click is run.

Java Identifiers and keywords

(1) Identifiers

An identifier is a name used to identify a valid sequence of characters for a class name, variable name, method name, array name, and file name. It consists of letters, numbers, underscores, dollar signs, and the first symbol cannot be a number.

PS: Identifiers are case-sensitive.

(2) Keywords

Keywords are words that have been given a particular meaning in the Java language and cannot be used as identifiers. The keywords are shown in the following table.

Use of Eclipse and Java program identifiers and keywords