实验报告实验一
【实验名称】 实验1 Java程序设计基础 【实验目标】 1、学习和掌握Java程序的基本结构。
2、学习和掌握Java程序的基本开发过程和方法。
3、学习和掌握程序设计的基本开发步骤。
4、学习和掌握Java程序的基本输入、输出方法。
5、学习和掌握Java程序设计的基本技.【实验日期和时间记录】2014.4.18-2014.4.26 1.创建、编译和执行 Welcome.java。
【 实验预习】 练习利用 Java 输出简单语句。
【实验过程及结果记录】 public class Welcome{ public static void main(String[] args){ System.out.println(“Wlecome to Java！”);}
} 2、（财务应用程序：工资单）编写程序，读入工资基本信息并 打印工资单。编写两种版本的程序，依次使用控制台实现输入输出和 GUI 实现输入输出。运行效果可参见图 1 和图 2。
【实验预习】 练习GUI 输入输出，键盘输入，存在一个变量里面,整体输出。
【实验过程及结果记录】 控制台界面 /** * @(#)ComputeAndShowSolary.java * * * @author * @version 1.00 2014/4/12 */
import java.util.Scanner;// public class ComputeAndShowSolary { public static void main(String[] args){ //input section System.out.print("Enter employee"s name:");//Promt the user to enter a name Scanner input= new Scanner(System.in);String name=input.nextLine();//input the name System.out.print("Enter number of hours worked in a week:");//Promt the user to enter number of hours double workhour=input.nextDouble();//input the hour System.out.print("Enter hourly pay rate:");//Promt the user to enter the rate double payrate=input.nextDouble();//input the rate System.out.print("Enter federal tax Withholding rate:");//Promt the user to enter the federal tax rate double federalrate=input.nextDouble();//input the
federal tax rate System.out.print("Enter state tax Withholding rate:");//promt the user to enter the state tax rate double staterate=input.nextDouble();//inout the state tax rate //output section System.out.println(" 雇员姓名: "+name);//output employee"s name System.out.println(" 工 作 小 时 数 : "+workhour);//output hours worked System.out.println(" 每 小 时 工 资 数 : "+"$"+payrate);//output pay rate System.out.println(" 工 资 总 收 入 : "+"$"+payrate*workhour);//output payrate System.out.println(" 所 纳 税 款 :");//output Deductions System.out.println(" 联 邦 税"+"("+federalrate*100+"%"+")"+":
"+"$"+workhour*payrate*federalrate);System.out.println(" 州 税"+"("+staterate*100+"%"+")"+": "+"$"+workhour*payrate*staterate);System.out.printf("总纳税: "+"$");System.out.printf("%.2fn",workhour*payrate*(0.2+0.09));System.out.printf("净收入: "+"$");System.out.printf("%.2f",workhour*payrate*(1.0-0.2-0.09));} } GUI 界面 /** * @(#)ComputeAndShowSolaryWithGUI.java
* * * @author * @version 1.00 2014/4/12 */ import javax.swing.JOptionPane;public class ComputeAndShowSolaryWithGUI { public static void main(String[] args){ //input section String namestring=JOptionPane.showInputDialog("Enter employee"s name:");String hoursstring=JOptionPane.showInputDialog("Enter numbers of hours worked in a week:");
int hours=Integer.parseInt(hoursstring);String payratestring=JOptionPane.showInputDialog("Enter hourly pay rate:");double payrate=Double.parseDouble(payratestring);String federalstring=JOptionPane.showInputDialog("Enter federal tax withholding rate:");double federal=Double.parseDouble(federalstring);String statestring=JOptionPane.showInputDialog("Enter state tax withholding rate:");double state=Double.parseDouble(statestring);//output section
JOptionPane.showMessageDialog(null, "雇员姓名: "+namestring+ "n 工作小时数："+hours+ "n 每小时工资数："+"$"+payrate+ "n 工资总收入："+ "$"+payrate*hours+ "n 所纳税款："+ "n 联 邦 税(20.0%):"+"$"+hours*payrate*0.2+ "n 州 税(9.0%):"+"$"+(int)(hours*payrate*0.09*100)/100.0+ "n 总 纳 税 ："+"$"+(int)(hours*payrate*(0.2+0.09)*100)/100.00+ "n 净 收 入 ："+"$"+(int)(hours*payrate*(1.0-0.2-0.09)*100)/100.00);}
} 3、（财务应用程序：计算税款）按照表1，基于纳税人的身份和可征税收入，编写程序，计算某个纳税人的纳税额。比如，计算一个收入400000美元的单身纳税人的纳税额。程序的运行效果见图3。
说明：⑴题目来源，编程练习3.13（P85）和程序清单 3-6(P68)。⑵程序设计的基本步骤，参见 2.2 小节（P18）和教材 P84 给出的教学注意。⑶解决方案的选择模型，参见授课 ppt 文稿。
【实验预习】 练习if 语句和基本运算语句 【实验过程及结果记录】 import java.util.Scanner;public class ComputeTax{
public static void main(String[] args){ System.out.println("(0-单身纳税人。1-已婚共同纳税人或证实的鳏寡，2-已婚单独纳税人，3-家庭户主纳税人)");System.out.print("Enter the filing status:");Scanner input=new Scanner(System.in);int choice=input.nextInt();System.out.print("Enter the taxable income:");double income=input.nextDouble();double tax=0;if(0==choice){ if(0<=income&&income<=8350){ tax=income*0.1;} else if(8351<=income&&income<=33950){ tax=8350*0.1+(income-8350)*0.15;}
else if(33951<=income&&income<=82250){ tax=8350*0.1+(33950-8350)*0.15+(income-33950)*0.25;} else if(82251<=income&&income<=171550){ tax=8350*0.1+(33950-8350)*0.15+(82250-33950)*0.25+(income-82250)*0.28;} else if(171551<=income&&income<=372950){ tax=8350*0.1+(33950-8350)*0.15+(82250-33950)*0.25+(171550-82250)*0.28+(income-171550)*0.33;} else if(372951<=income){ tax=8350*0.1+(33950-8350)*0.15+(82250-33950)*0.25+(171550-82250)*0.28+(372950-171550)*0.33+(income-372950)*0.35;
} } if(1==choice){ if(0<=income&&income<=16700){ tax=income*0.1;} else if(16701<=income&&income<=67900){ tax=16700*0.1+(income-16700)*0.15;} else if(67901<=income&&income<=137050){ tax=16700*0.1+(67900-16700)*0.15+(income-67900)*0.25;}
else if(137051<=income&&income<=208850){ tax=16700*0.1+(67900-16700)*0.15+(137050-67900)*0.25+(income-13751)*0.28;} else if(208851<=income&&income<=372950){ tax=16700*0.1+(67900-16700)*0.15+(137050-67900)*0.25+(208850-13751)*0.28+(income-208850)*0.33;} else if(372951<=income){ tax=16700*0.1+(67900-16700)*0.15+(137050-67900)*0.25+(208850-13750)*0.28+(372950-208850)*0.33+(income-372950)*0.35;} }
if(2==choice){ if(0<=income&&income<=8350){ tax=income*0.1;} else if(8351<=income&&income<=33950){ tax=8350*0.1+(income-8350)*0.15;} else if(33951<=income&&income<=67525){ tax=8350*0.1+(33950-8350)*0.15+(income-33950)*0.25;} else if(68526<=income&&income<=104425){ tax=8350*0.1+(33950-8350)*0.15+(68525-33950)*0.25+(income-68525)*0.28;}
else if(104426<=income&&income<=186475){ tax=8350*0.1+(33950-8350)*0.15+(68525-33950)*0.25+(104425-68525)*0.28+(income-171550)*0.33;} else if(186476<=income){ tax=8350*0.1+(33950-8350)*0.15+(68525-33950)*0.25+(104425-68525)*0.28+(186745-104425)*0.33+(income-372950)*0.35;} } if(3==choice){ if(0<=income&&income<=11950){ tax=income*0.1;
} else if(11951<=income&&income<=45500){ tax=11951*0.1+(income-11950)*0.15;} else if(45501<=income&&income<=117450){ tax=11951*0.1+(45500-11950)*0.15+(income-45500)*0.25;} else if(117451<=income&&income<=190200){ tax=11951*0.1+(45500-11950)*0.15+(1175450-45500)*0.25+(income-117450)*0.28;} else if(190201<=income&&income<=372950){ tax=11951*0.1+(45500-11950)*0.15+(1175450-45500)*0.25+(190200-117450)*0.28+(income-171550)*0.33;}
else if(372951<=income){ tax=8350*0.1+(33950-8350)*0.15+(82250-33950)*0.25+(171550-82250)*0.28+(372950-171550)*0.33+(income-372950)*0.35;} } System.out.println("Tax is "+tax);} } 4、（财务应用程序：打印税表）在问题3的基础上，使用下面的方法头部，编写一个计算税款的方法：
public static double computeTax()int status,double taxableIncome)使用这个方法编写程序，打印可征税收入从50000美元到60000美元，收入间隔50美元的所有四种纳税人的纳税表。
【实验预习】
练习if 语句，以及方法的使用 【实验过程及结果记录】 /** * @(#)NewComputeTax.java * * * @author * @version 1.00 2014/5/4 */ public class NewComputeTax { public static double computeTax(int status,double taxableIncome){ double tax=0;double income=taxableIncome;int choice=status;
if(0==choice){ if(0<=income&&income<=8350){ tax=income*0.1;} else if(8351<=income&&income<=33950){ tax=8350*0.1+(income-8350)*0.15;} else if(33951<=income&&income<=82250){ tax=8350*0.1+(33950-8350)*0.15+(income-33950)*0.25;} else if(82251<=income&&income<=171550){ tax=8350*0.1+(33950-8350)*0.15+(82250-33950)*0.25+(income-82250)*0.28;} else if(171551<=income&&income<=372950){
tax=8350*0.1+(33950-8350)*0.15+(82250-33950)*0.25+(171550-82250)*0.28+(income-171550)*0.33;} else if(372951<=income){ tax=8350*0.1+(33950-8350)*0.15+(82250-33950)*0.25+(171550-82250)*0.28+(372950-171550)*0.33+(income-372950)*0.35;} } if(1==choice){ if(0<=income&&income<=16700){ tax=income*0.1;} else if(16701<=income&&income<=67900){ tax=16700*0.1+(income-16700)*0.15;
} else if(67901<=income&&income<=137050){ tax=16700*0.1+(67900-16700)*0.15+(income-67900)*0.25;} else if(137051<=income&&income<=208850){ tax=16700*0.1+(67900-16700)*0.15+(137050-67900)*0.25+(income-13751)*0.28;} else if(208851<=income&&income<=372950){ tax=16700*0.1+(67900-16700)*0.15+(137050-67900)*0.25+(208850-13751)*0.28+(income-208850)*0.33;} else if(372951<=income){ tax=16700*0.1+(67900-16700)*0.15+(137050-67900)*0.25+(208850-13750)*0.28+(372950-208850)*0.33+(income-372950)*
0.35;} } if(2==choice){ if(0<=income&&income<=8350){ tax=income*0.1;} else if(8351<=income&&income<=33950){ tax=8350*0.1+(income-8350)*0.15;} else if(33951<=income&&income<=67525){ tax=8350*0.1+(33950-8350)*0.15+(income-33950)*0.25;} else if(68526<=income&&income<=104425){
tax=8350*0.1+(33950-8350)*0.15+(68525-33950)*0.25+(income-68525)*0.28;} else if(104426<=income&&income<=186475){ tax=8350*0.1+(33950-8350)*0.15+(68525-33950)*0.25+(104425-68525)*0.28+(income-171550)*0.33;} else if(186476<=income){ tax=8350*0.1+(33950-8350)*0.15+(68525-33950)*0.25+(104425-68525)*0.28+(186745-104425)*0.33+(income-372950)*0.35;} }
if(3==choice){ if(0<=income&&income<=11950){ tax=income*0.1;} else if(11951<=income&&income<=45500){ tax=11951*0.1+(income-11950)*0.15;} else if(45501<=income&&income<=117450){ tax=11951*0.1+(45500-11950)*0.15+(income-45500)*0.25;} else if(117451<=income&&income<=190200){ tax=11951*0.1+(45500-11950)*0.15+(1175450-45500)*0.25+(income-117450)*0.28;} else if(190201<=income&&income<=372950){
tax=11951*0.1+(45500-11950)*0.15+(1175450-45500)*0.25+(190200-117450)*0.28+(income-171550)*0.33;} else if(372951<=income){ tax=8350*0.1+(33950-8350)*0.15+(82250-33950)*0.25+(171550-82250)*0.28+(372950-171550)*0.33+(income-372950)*0.35;} } System.out.println(choice+" "+income+" "+tax);return 0;} public static void main(String[] args){ for(int status=0;status<4;status++){ for(double income=50000;income<=60000;income+=50){ computeTax(status,income);}
} } } 5、（财务应用程序：计算税款）使用数组重新编写问题3的实现。使用数组表示税率：
double[] rates = {0.10,0.15,0.25,0.28,0.33,0.35};使用数组表示收入分段：
int[][] brackets = { {8350,33950,82250,171550,372950}, {16700,67900,137050,208850,372950}, {8350,33950,68525,104425,186475}, {11950,45500,117450,190200,372950} };【实验预习】 练习数组的输入输出以及处理数组内的数据。
【实验过程及结果记录】 /**
* @(#)ComputeTaxWithArray.java * * * @author * @version 1.00 2014/5/4 */ import java.util.Scanner;public class ComputeTaxWithArray { public static void main(String[] args){ // Create a Scanner Scanner input = new Scanner(System.in);// Prompt the user to enter filing status // Prompt the user to enter filing status System.out.print（"(0-single filer, 1-married jointly,n" + "2-married separately, 3-head of household)n" + "Enter the filing status: ");int status = input.nextInt();// Prompt the user to enter taxable income System.out.print("Enter the taxable income: ");double income = input.nextDouble();// Compute and display the result System.out.println("Tax is " +(int)(computeTax(status, income)* 100)/ 100.0);} public static double computeTax(int status, double income){ double[] rates = {0.10, 0.15, 0.25, 0.28, 0.33，0.35};int[][] brackets = { {8350, 33950, 82250, 171550, 372950}, // Single filer {16700, 67900, 137050, 20885, 372950}, // Married jointly {8350, 33950, 68525, 104425, 186475}, // Married separately {11950, 45500, 117450, 190200, 372950} // Head of household };double tax = 0;// Tax to be computed // Compute tax in the first bracket if(income <= brackets[status][0])return tax = income * rates[0];// Done
else tax = brackets[status][0] * rates[0];// Compute tax in the 2nd, 3rd, 4th, and 5th brackets, if needed for(int i = 1;i < brackets[0].length;i++){ if(income > brackets[status][i])tax +=(brackets[status][i]-brackets[status][i-1])* rates[i];else { tax +=(income-brackets[status][i-1])* rates[i];return tax;// Done } } // Compute tax in the last(i.e., 6th)bracket
return tax +=(income-brackets[status][4])* rates[5];} } 【思考题】 你开始“每天做一点编程练习”了吗？ 已经坚持了一段时间 在问题 3 的解决方案中，你使用的是哪种选择结构模型（可以使用流程图描述）？实现这个选择结构模型的 java 语法结构是什么？ 先判断纳税人的情况，根据纳税人情况再对其收入进行分析以确定其应缴多少的税；使用的事 if 选择结构 在问题 4 中，你使用了哪种循环方法？为什么？ for 循环；循环开始，终止条件一目了然 你如何理解教材作者说的“如果能够使用循环编写程序，你就懂得如何编程了”？（语出教材 P103）利用循环可以简化语句，熟练地掌握编程语言
从问题 3 到问题 5，可以使用不同的编程技术，解决同一个问题。说说你对这个过程中的编程感受和想法？ 编程的方法是多种多样的，不可局限于某一种方法。
