1、一个源文件只能有一个public class中,不能在已经已经有public class的源文件中再次定义public class。-------------------------幻腾寂埒-/*** This program displays a greeting from the authors.** @version 1.20 2004-02-28* @author Cay Horstmann*/public class Welcome { public static void main(String[] args) { System.out.println("Welcome to Core Java"); }}public class Welcome2 { public static void main(String[] args) { System.out.println("Welcome to Core Java"); }}

3、一个源文件可以定义多个类,但是,只能有一个是public class。------------------------------------------------------------------/*** This program displays a greeting from the authors.** @version 1.20 2004-02-28* @author Cay Horstmann*/public class Welcome { public static void main(String[] args) { System.out.println("Welcome to Core Java"); }}class Welcome2 { public static void main(String[] args) { System.out.println("Welcome to Core Java");

5、编译后产生两个类的class文件。

7、源文件的名字必须和public class的名字一样,大写敏感。-颍骈城茇---------------------------------------------------------命名为W髫潋啜缅elcome2.java----------------------------------------------------------/*** This program displays a greeting from the authors.** @version 1.20 2004-02-28* @author Cay Horstmann*/public class Welcome { public static void main(String[] args) { System.out.println("Welcome to Core Java"); }}class Welcome2 { public static void main(String[] args) { System.out.println("Welcome to Core Java"); }}

9、源文件的名字必须和public class的名字一样,大写敏感。-颍骈城茇---------------------------------------------------------命名为w髫潋啜缅elcome.java----------------------------------------------------------/*** This program displays a greeting from the authors.** @version 1.20 2004-02-28* @author Cay Horstmann*/public class Welcome {public static void main(String[] args) {System.out.println("Welcome to Core Java");}}class Welcome2 {public static void main(String[] args) {System.out.println("Welcome to Core Java");}}
