上机作业5.28

package yidong;

import java.util.Random;

public class Text {

	public static void main(String[] args) {
		int a[] = new int[10];
		Random r = new Random();
		for (int i = 0; i < a.length; i++) {
			a[i] = r.nextInt(100);
		}
		for (int i = 0; i < a.length; i++) {
			System.out.println(a[i]);
		}
	}

}

　　

package yidong;

import java.text.SimpleDateFormat;
import java.util.Date;

public class Text {
	public static void main(String[] args) {
		Date c = new Date();
		SimpleDateFormat a1 = new SimpleDateFormat("Eyyyy年MM月dd日");
		SimpleDateFormat a2 = new SimpleDateFormat("今天是Eyyyy年的第 D 天 ，E");
		System.out.println(a1.format(c));
		System.out.println(a2.format(c));

	}
}

　　

package yidong;
import java.util.Scanner;
public class Text {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("请输入合法的邮箱：");
        String s = input.nextLine();
        int a = 0;
        int b = 0;
        int x = 0;
        int y = 0;
        for (int i= 0; i < s.length() - 1; i++) {
            String str = s.substring(i, i + 1);
            if (str.equals("@")) {
                a++;
                x = i;
            }
            if (str.equals(".")) {
               b++;
                y = i;
            }
        }
        if (a == 1 &&b == 1 && x < (y - 1) && x != 0 && y != s.length() - 1) {
           s.endsWith("@qq.com");
            System.out.println("合法");
        } else {
            System.out.println("不合法");
        }
        String s1 = s.substring(0, s.indexOf("@"));
		System.out.println("用户名是："+s1);
    }
}