2017-12-19作业 if和switch的使用

时间有多改成了方法，可以正常运行。

导入栏：

package day1219;import java.util.Scanner;public class entry {public static void main(String[] args){System.out.print("请输入你要查看的作业：");Scanner a = new Scanner(System.in);String a1 = a.next();//System.out.print(a1);for(int i = 0;i<25;i++){System.out.print(" * ");}System.out.println();if(a1.equals("homework1")){homework1 s = new homework1();s.run();}else if(a1.equals("homework2")){homework2 s = new homework2();s.run(); }else if(a1.equals("homework3")){ homework3 s = new homework3();s.run(); }else if(a1.equals("homework4")){ homework4 s = new homework4();s.run(); }else{ System.out.println("您输入的作业不存在!"); System.out.println("没有找到此作业!"); }}}

homework1：

/** * 2:输入赵本山的考试成绩，显示所获奖励成绩==100分，爸爸给他买辆车成绩>=90分，妈妈给他买MP490分>成绩>=60分，妈妈给他买本参考书成绩<60分，什么都不买 */package day1219;import java.util.Scanner;public class homework1 {public static void run(){System.out.print("输入赵本山的考试成绩，显示所获奖励：");Scanner a = new Scanner(System.in);int sroce = a.nextInt();if(sroce>100||sroce<0){System.out.println("输入有误");}else if(sroce == 100){System.out.println("阿爸给你买辆车");}else if(sroce>=90&&sroce<100){System.out.println("阿妈给你买MP4");}else if(sroce>=60&&sroce<90){System.out.println("阿妈给你买本参考书");}else{System.out.println("什么都不买");}}}

homework2：

/** * 3:由控制台输入两个整数，获取两个数据中较大的值 */package day1219;import java.util.Scanner;public class homework2 {public static void run(){Scanner a = new Scanner(System.in);System.out.print("请输入第一个数：");int a1 = a.nextInt();System.out.print("请输入第二个数：");int a2 = a.nextInt();if(a1>a2){System.out.println("第一个数的值较大，第一个数的值为：" + a1);}else if(a1<a2){System.out.println("第二个数的值较大，第二个数的值为：" + a2);}else{System.out.println("两个数的值一样大，两个数的值为：" + a1);}}}

homework3：

/** * 4:由控制台输入一个整数,判断该整数是奇书还是偶数 */package day1219;import java.util.Scanner;public class homework3 {public static void run(){Scanner a = new Scanner(System.in);System.out.print("请输入一个整数：");int a1 = a.nextInt();if(a1%2==0){System.out.println("这个数是一个偶数!");}else{System.out.println("这个数是一个奇数!");}}}

homework4：

/** * 输入3个数并从小到大排序 */package day1219;import java.util.Scanner;public class homework4 {public static void run(){Scanner a = new Scanner(System.in);System.out.print("请输入第一个数：");int a1 = a.nextInt();System.out.print("请输入第二个数：");int a2 = a.nextInt();System.out.print("请输入第三个数：");int a3 = a.nextInt();//傻瓜方法//if(a1>=a2&&a2>=a3){//System.out.println(a1+","+a2+","+a3);//}else if(a1>=a3&&a3>=a2){//System.out.println(a1+","+a3+","+a2);//}else if(a1<=a2&&a2<=a3){//System.out.println(a3+","+a2+","+a1);//}else if(a2<=a1&&a3>=a1){//System.out.println(a3+","+a1+","+a2);//}else if(a1<=a2&&a3<=a1){//System.out.println(a2+","+a1+","+a3);//}else if(a1<=a3&&a2>=a3){//System.out.println(a2+","+a3+","+a1);//}//选择排序int[] arr = {a1,a2,a3};for(int x = 0;x<arr.length-1;x++){for(int y = x+1;y<arr.length;y++){if(arr[x]>arr[y]){int temp = arr[x];arr[x] = arr[y];arr[y] = temp;}}}for(int x = 0;x<arr.length;x++){System.out.print(arr[x]+",");}}}