Java语言程序设计基础篇原书第十版第二章编程练习题答案

程序如有问题，及时联系博主哦~博主会贴出所有带有星号的题目，以及一些典型的例子，希望能够帮助到同学们，也希望同学们都学好java语言。

2.1将摄氏温度转换为华氏温度

package nameyu;import java.util.Scanner;public class Test {/*** @param args*/public static void main(String[] args) {// TODO Auto-generated method stubScanner input=new Scanner(System.in);System.out.print("Enter a degree in celsius:");double Celsiustemperature=input.nextDouble();double Fahrenheit=(9.0/5)*Celsiustemperature+32;System.out.println(Celsiustemperature+"Cellsius is "+Fahrenheit+" Fahrenheit");}}

2.5财务应用小程序：计算小费

package nameyu;import java.util.Scanner;public class Test {/*** @param args*/public static void main(String[] args) {// TODO Auto-generated method stubScanner input=new Scanner (System.in);System.out.print("Enter the subtotal and a gratuity rate:");double subtotal=input.nextDouble();double gratuityrate=input.nextDouble();double gratuity=subtotal*gratuityrate*0.01;double total=subtotal+gratuity;System.out.println("The gratuity is $"+gratuity+" and total is $"+total);}}

2.6求一个整数各位数的和

package nameyu;import java.util.Scanner;public class Test {/*** @param args*/public static void main(String[] args) {// TODO Auto-generated method stubScanner input=new Scanner(System.in);System.out.print("Enter a number 0 and 1000 :");int number =input.nextInt();int bit=number%10;number=number/10;int ten=number%10;number=number/10;int kil=number%10;System.out.println("The sum of the digits is "+(bit+ten+kil));}}这是一种没有循环的做法，比较死板，但是很容易理解，下面介绍一种好的方法

续上：

package nameyu;import java.util.Scanner;public class Test {/*** @param args*/public static void main(String[] args) {// TODO Auto-generated method stubScanner input=new Scanner(System.in);System.out.print("Enter a number 0 and 1000 :");int number =input.nextInt();int sum=0;while(number/10!=0){sum=sum+number%10;number=number/10;}sum=sum+number;System.out.println("The sum of the digtits is :"+sum);}}

2.7求出年数

package nameyu;import java.util.Scanner;public class Test {/*** @param args*/public static void main(String[] args) {// TODO Auto-generated method stubScanner input=new Scanner(System.in);System.out.print("Enter the number of minutes :");int number =input.nextInt();int years=number/(60*24*365);//int days=number%(60*24*365);int days=number/(60*24)-years*365;System.out.println(days);}}

2.8当前时间

package nameyu;import java.util.Scanner;public class Test {/*** @param args*/public static void main(String[] args) {// TODO Auto-generated method stubScanner input=new Scanner(System.in);System.out.print("Enter the time zone offset to GMT :");int GMT =input.nextInt();long totalMilliseconds=System.currentTimeMillis();long totalSeconds=totalMilliseconds/1000; long currentSecond=totalSeconds%60;long totalMinutes=totalSeconds/60;long currentMinutes=totalSeconds%60;long totalHours=totalMinutes/60;long currentHours=totalHours%24;System.out.println("Current time is"+(currentHours+GMT)+":"+currentMinutes+":"+currentSecond);}

2.13（财务应用程序）复利值

package nameyu;import java.util.Scanner;public class Test {/*** @param args*/public static void main(String[] args) {// TODO Auto-generated method stubScanner input=new Scanner(System.in);System.out.print("Enter the monthly saving amount and mouth:");double save=input.nextDouble();int mouths=input.nextInt();double yearsrate=0.05;double mouthrate=(yearsrate/12);double total=0;for(int i=1;i<=mouths;i++){total=(total+save)*(1+mouthrate);}System.out.println((int)(total*100)/100.0);}}

2.14医疗应用程序：计算BMI

package nameyu;import java.util.Scanner;public class Test {/*** @param args*/public static void main(String[] args) {// TODO Auto-generated method stubScanner input=new Scanner(System.in);System.out.print("Enter weight in pounds:");double weight=input.nextDouble();System.out.print("Enter height in inches:");double height=input.nextDouble();double rice=height*0.0254;double kg=weight*0.45359237;double BMI=kg/(rice*rice);System.out.println("BMI is"+BMI);}}

2.17科学，风寒温度

package nameyu;import java.util.Scanner;public class Test {/*** @param args*/public static void main(String[] args) {// TODO Auto-generated method stubScanner input=new Scanner(System.in);System.out.print("Enter the temperature in Fahrenheit between -58°F and 41°F:");double Fahrenheit=input.nextDouble();System.out.print("Enter the wind speed (x>=2) in miles per hour:");double speed=input.nextDouble();if(speed>=2&&Fahrenheit>-58&Fahrenheit<41){double twc=35.74+0.6215*Fahrenheit-35.75*Math.pow(speed, 0.16)+0.4275*Fahrenheit*Math.pow(speed, 0.16);System.out.println(twc);}elseSystem.out.println("error");}}

2.18打印表格

package nameyu;//import java.util.Scanner;public class Test {/*** @param args*/public static void main(String[] args) {// TODO Auto-generated method stubSystem.out.printf("%-5s%-5s%-5s%n", "a","b","pow(a,b)");/*这个地方可能有的同学会有问题，使用printf或者format输出的时候，有的机器需要在window里面配置如果有任何问题可以邮件联系博主，有时间我会把教程发在博客中。*/for (int i=1;i<6;i++){int s=(int)Math.pow(i, i+1);System.out.printf("%-5d%-5d%-5d%n", i,i+1,s);}}}

2.19几何：三角形的面积

package nameyu;import java.util.Scanner;public class Test {/*** @param args*/public static void main(String[] args) {// TODO Auto-generated method stubScanner input=new Scanner(System.in);System.out.println("Enter three points for a triangle :");double x1=input.nextDouble();double y1=input.nextDouble();double x2=input.nextDouble();double y2=input.nextDouble();double x3=input.nextDouble();double y3=input.nextDouble();double s1=Math.sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));double s2=Math.sqrt((x3-x1)*(x3-x1)+(y3-y1)*(y3-y1));double s3=Math.sqrt((x3-x2)*(x3-x2)+(y3-y2)*(y3-y2));double s=(s1+s2+s3)/2;double area=Math.sqrt(s*(s-s1)*(s-s2)*(s-s3));System.out.println("The area of the triangle is "+(int)(area*10)/10.0);} }

2.20财务应用程序：计算利息

package nameyu;import java.util.Scanner;public class Test {/*** @param args*/public static void main(String[] args) {// TODO Auto-generated method stubScanner input=new Scanner(System.in);System.out.println("Enter balance and interest rate(e.g.,3 for 3%):");double money=input.nextDouble();double rate=input.nextDouble();double interest=money*(rate/1200);System.out.println("The interest is "+(int)(interest*100000)/100000.0);}}

2.22财务应用:货币单位

package nameyu;import java.util.Scanner;public class Test {/*** @param args*/public static void main(String[] args) {// TODO Auto-generated method stubScanner input=new Scanner(System.in);System.out.print("Enter an amount in int,for example 1156($11.56):");int amount=input.nextInt();int dollar=amount/100;int cent=amount%100;System.out.println("This amout ="+dollar+"."+cent);}}

这一章的课后编程题大概也就是这些了，重点的都已经给出了代码，并且亲自测试了的，有出错或者什么问题的都可以联系博主。编写代码不容易，兄弟们帮忙顶顶