/*3-2.程序员：龚猛
第三章全部例题*/
1 package zhenshu;
2 import java.util.Scanner;
3 public class practise {
4
5 public static void main(String[] args) {
6 int number1 = (int)(Math.random() * 10);
7 int number2 = (int)(Math.random() * 10);
8
9 if(number1 < number2) {
10 int temp = number1;
11 number1 = number2;
12 number2 = temp;
13 }
14 System.out.print
15 ("what is" + number1 + "-" + number2 +"?");
16 Scanner input = new Scanner(System.in);
17 int answer = input.nextInt();
18
19 if (number1 - number2 == answer)
20 System.out.println("You are correct!");
21 else{
22 System.out.println("Your answer is wrong.");
23 System.out.println(number1 + "-" + number2 + "should be" + (number1 - number2 ));
24 }
25 }
26
27 }
/*3-3.*/
1 package zhenshu; 2 import java.util.Scanner; 3 public class Demo { 4
5 public static void main(String[] args) { 6 Scanner input = new Scanner (System.in); 7 System.out.println("Enter an integer:"); 8 int number = input.nextInt(); 9
10 if (number % 5 ==0) 11 System.out.println("HiFive"); 12
13 if (number % 2 ==0) 14 System.out.println("HiEven"); 15
16 } 17
18 }
/*3-3*/
1 package zhenshu;
2 import java.util.Scanner;
3 public class bmi {
4
5 private static final char[] Obese = null;
6
7 public static void main(String[] args) {
8 Scanner input = new Scanner(System.in);
9
10 System.out.print("Enter height in pounds:");
11 double weight = input.nextDouble();
12
13 System.out.print("Enter height in inches:");
14 double height = input.nextDouble();
15
16 final double KILOGRAMS_PER_POUND = 0.45359237;
17 final double METERS_PER_INCH = 0.0254;
18
19 double weightInKilograms = weight * KILOGRAMS_PER_POUND;
20 double heightInMeters = height * METERS_PER_INCH;
21 double bmi = weightInKilograms / (heightInMeters * heightInMeters);
22
23 System.out.println("BMI is" + bmi);
24 if (bmi < 18.5)
25 System.out.println("Underweight");
26 else if (bmi < 25)
27 System.out.println("Normal");
28 else if (bmi < 30)
29 System.out.println("overweight");
30 else
31 System.out.println(Obese);
32
33
34 }
35
36 }
