第一章 计算机、程序和Java概述 课本源代码

//程序清单1-1 Welcome-java
public class Welcome
{
public static void main(String[] args)
{
//Display message Welcome t java ! to the console
System.out.println("Welcome to Java!");
}

}

//程序清单1-2 welcome1.java
public class Welcome1
{
public static void main(String[] args)
{
System.out.println("Programming is fun!");
System.out.println("Fundamentals First");
System.out.println("Problem Driven");
}
}

//程序清单1-3 ComputeExpression.java
public class ComputeExperssion
{
public static void main(String[] args)
{
System.out.println((10.5+2*3)/(45-3.5));
}
}

//程序清单1-4 WelcomeInMessageDialogBox.java
/* This application program displays Welcome to Java!
* in a message dialog box
* 功能：在对话框中输出“welcome to Java!"
*/
import javax.swing.JOptionPane;

public class WelcomeInMessageDialogBox
{
public static void main(String [] args)
{
//输出“Welcome to Java”
JOptionPane.showMessageDialog(null,"Welcome to Java!");
}
}