Java-how-to-program(第六版)答案第六章--1

1、第六章 方法的深入剖析6.7結(jié)果如下：a)7.5b)7.0c)0.0d)0.0e)6.4f)6.0g)-14.06.8程序代碼為：import java.util.Scanner;public class Exercise1_2 public static void main( String args) Exercise1_2 e = new Exercise1_2(); Scanner input = new Scanner( System.in ); int time; double account = 0.0; System.out.println("Enter the par

2、k time or end with -1:"); time = input.nextInt(); while ( time != -1 ) System.out.printf("Charge with $%.3fn", e.calculateCharge( time ); account += e.calculateCharge( time ); System.out.println("Enter the park time or end with -1:"); time = input.nextInt(); System.out.print

3、f("The total park money is $%.3f.", account); public double calculateCharge( int time )double charge;if ( time <= 3 )charge = 2.00;else if ( time <= 24 )charge = 2.00+(time-3)*0.50;elsecharge = 10.00;return charge;6.9程序?yàn)椋篿mport java.util.Scanner;public class Exercise1 /* * param args

4、 */public static void main(String args) / TODO Auto-generated method stubScanner input = new Scanner(System.in);double number;int result;System.out.println("Enter a number :");number = input.nextDouble();result = (int)Math.floor(number+0.5);System.out.printf("Before %.3fnAfter %dn&quo

5、t;, number, result);6.10程序代碼為：import java.util.Scanner;public class Exercise1 /* * param args */public static void main(String args) / TODO Auto-generated method stubExercise1 e = new Exercise1();Scanner input = new Scanner(System.in);double number;System.out.println("Enter a number :");nu

6、mber = input.nextDouble();System.out.printf("The original number is %.3fn", number); System.out.printf("Rounding to the integer is %dn",e.roundToInteger(number);System.out.printf("Rounding to the tenths is %.1fn", e.roundToTenths(number);System.out.printf("Rounding

7、 to the hundredths is %.2fn", e.roundToHundredths(number);System.out.printf("Rounding to the thousands is %.3fn",e.roundToThousandsths(number);public int roundToInteger( double number )return (int)Math.floor(number+0.5);public double roundToTenths( double number )return Math.floor(num

8、ber*10+0.5)/10;public double roundToHundredths( double number )return Math.floor(number*100+0.5)/100;public double roundToThousandsths( double number )return Math.floor(number*1000+0.5)/1000;6.11 a)隨機(jī)意味著公平的原則，即概率相等b)屬于計(jì)算機(jī)隨機(jī)取值，也就保證了游戲的公平性c)為了符合實(shí)際情況，故需要縮放或變換random的值d)由于計(jì)算機(jī)計(jì)算的隨機(jī)性和公平性對(duì)于解決一些實(shí)際問(wèn)題更方便6.12 a

9、) n = 1 + randmNumbers.nextInt(2);b)n = 1 + randmNumbers.nextInt(100);c)n = 1 + randmNumbers.nextInt(9);d)n = 1000 + randmNumbers.nextInt(112);e)n = -1 + randmNumbers.nextInt(2);f)n = -3 + randmNumbers.nextInt(14);6.13語(yǔ)句如下：a)n = 2*(randmNumbers.nextInt(5)+1);b)n = 2*(randmNumbers.nextInt(5)+1)+1;c)n

10、 = 4*(randmNumbers.nextInt(5)+1)+2;6.14程序?yàn)椋篿mport java.util.Scanner;public class Exercise5 /* * param args */public static void main(String args) / TODO Auto-generated method stubScanner input = new Scanner( System.in );int base;int exponent;int result;System.out.println("Enter base and exponen

11、t number :");base = input.nextInt();exponent = input.nextInt();result = integerPower( base, exponent );System.out.println("The integer power is :" +result);public static int integerPower( int base , int exponent )int i;int result = 1;for ( i=1; i<=exponent; i+ )result *= base;retur

12、n result;6.15程序代碼為：import java.util.Scanner;public class Exercise5 /* * param args */public static void main(String args) / TODO Auto-generated method stubScanner input = new Scanner( System.in );double side1;double side2;double hyp;System.out.println("Enter side1 and side2:");side1 = inpu

13、t.nextDouble();side2 = input.nextDouble();hyp = hypotenuse( side1, side2 );System.out.printf("The hypotenuse is :%.2f", hyp);public static double hypotenuse( double side1, double side2 )double hyp;hyp = Math.pow(side1*side1+side2*side2), 0.5);return hyp;6.16程序代碼為：import java.util.Scanner;p

14、ublic class Exercise5 /* * param args */public static void main(String args) / TODO Auto-generated method stubScanner input = new Scanner( System.in );int num1;int num2;int result;System.out.println("Enter number1 and number2:");num1 = input.nextInt();num2 = input.nextInt();result = mutipl

15、e( num1, num2 );if ( result = 1 )System.out.printf("%d is %d mutiple.", num1, num2 );elseSystem.out.printf("%d is not %d mutiple.", num1, num2 );public static int mutiple( int number1, int number2 )if ( number1 % number2 = 0 )return 1;else return 0;6.17程序代碼為：public class Exercise

16、5 /* * param args */public static void main(String args) / TODO Auto-generated method stubScanner input = new Scanner( System.in );int num;int result;System.out.println("Enter number:");num = input.nextInt();while ( num != -1 ) result = isEven( num );if ( result = 1 )System.out.printf(&quo

17、t;%d is an even number.", num );elseSystem.out.printf("%d is an odd number.", num );System.out.println("Enter number:");num = input.nextInt();public static int isEven( int number )if ( number % 2 = 0 )return 1;else return 0;6.18程序代碼為：import java.util.Scanner;public class Exe

18、rcise5 /* * param args */public static void main(String args) / TODO Auto-generated method stubScanner input = new Scanner( System.in );int num;System.out.println("Enter number:");num = input.nextInt();System.out.println("The result is :");squareOfAsterisks( num );public static v

19、oid squareOfAsterisks( int number )int i;int j;for ( i=1; i<=number; i+ )for ( j=1; j<=number; j+ )System.out.print('*');System.out.println();6.19程序代碼為：import java.util.Scanner;public class Exercise5 /* * param args */public static void main(String args) / TODO Auto-generated method st

20、ubScanner input = new Scanner( System.in );int num;System.out.println("Enter number:");num = input.nextInt();System.out.println("The result is :");fillCharacter( num );public static void fillCharacter( int number )int i;int j;for ( i=1; i<=number; i+ )for ( j=1; j<=number;

21、j+ )System.out.print('#');System.out.println();6.20程序代碼為：import java.util.Scanner;public class Exercise5 /* * param args */public static void main(String args) / TODO Auto-generated method stubScanner input = new Scanner( System.in );double radius;System.out.println("Enter radius:"

22、);radius = input.nextDouble();System.out.printf("The area is :%.2f", circleArea( radius );public static double circleArea( double radius )return Math.PI*radius*radius;6.21程序代碼為：public class Exercise5 /* * param args */public static void main(String args) / TODO Auto-generated method stubSc

23、anner input = new Scanner( System.in );int number;System.out.println("Enter a number:");number = input.nextInt();System.out.println("The result is :");displayDigitals( number );public static void displayDigitals( int number )int a;int b;int c;int d;int e;a = number/10000;b = (num

24、ber/1000)%10;c = (number/100)%10;d = (number/10)%10;e = number%10;if ( a > 0 )System.out.printf("%-2d", a);System.out.printf("%-2d", b);System.out.printf("%-2d", c);System.out.printf("%-2d", d);System.out.printf("%-2d", e);else if ( b > 0 )Syst

25、em.out.printf("%-2d", b);System.out.printf("%-2d", c);System.out.printf("%-2d", d);System.out.printf("%-2d", e);else if ( c > 0 )System.out.printf("%-2d", c);System.out.printf("%-2d", d);System.out.printf("%-2d", e);else if ( d

26、 > 0 )System.out.printf("%-2d", d);System.out.printf("%-2d", e);elseSystem.out.printf("%-2d", e);6.22程序代碼為：import java.util.Scanner;public class Exercise1_3 /* * param args */public static void main(String args) / TODO Auto-generated method stubScanner input = new Sc

27、anner( System.in );double temperature;int temp;System.out.println("Enter 1 chage fahrenheit to Celsius");System.out.println("Enter 2 chage Celsius to fahrenheit");temp = input.nextInt();System.out.println("Enter the temperature:");temperature = input.nextDouble();if ( t

28、emp = 1 )celsius( temperature );elsefahrenheit( temperature );public static void celsius( double temperature )double degree;degree = 5.0/9.0*(temperature-32);System.out.printf("After changing to celsius,temperature is %.2f", degree);public static void fahrenheit( double temperature )double

29、 degree;degree = 9.0/5.0*temperature+32;System.out.printf("After changing to fahrenheit,temperature is %.2f", degree);6.23程序代碼為：import java.util.Scanner;public class Exercise1_2 public static void main( String args) Exercise1_2 e = new Exercise1_2();Scanner input = new Scanner( System.in ); double num1;double num2;double num3;double min;System.out.println("Enter three numbers:");num1 = input.nextDouble();num2 = input.nextDouble();num3 = input.nextDouble();min = e.minimum3( num1, num2, num3 );System.out.printf("The minimum number is :%.3f"