2021.10.12

**第一

package com.yingcan.Reward;

import java.util.Scanner;

public class Demo01 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入密码");
        if (scanner.hasNextLine()){
            String str =scanner.nextLine();
            System.out.println("输出的内容为："+str);
        }
        scanner.close();
    }
}





**第二

package com.yingcan.Reward;

import java.util.Scanner;

public class Demo02 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int i =0;
        float f =0.0f;
        System.out.println("请输入整数：");
        if (scanner.hasNextInt()){
            i =scanner.nextInt();
            System.out.println("输出的数据为整数"+i);
        }else{
            System.out.println("输出的数据不是整数");
        }
        System.out.println("请输入小数：");
        if (scanner.hasNextFloat()){
            f =scanner.nextFloat();
            System.out.println("输出的数据为小数"+f);
        }else{
            System.out.println("输出的数据不为小数" );
        }
        scanner.close();
    }
}

**第三

package com.yingcan.Reward;

import java.util.Scanner;

public class Demo03 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double sum =0;
        int m =0;
        System.out.println("请输入数据");
        while (scanner.hasNextDouble()){
            double x = scanner.nextDouble();
            m = m +1 ;
            sum =sum +x;
            System.out.println("你输入了第"+m+"个数据，这些数据的总和为sum="+sum);
            System.out.println("这些数据的平均值为"+(sum/m));
        }
        System.out.println(m+"这些数据的总和为"+sum);
        System.out.println(m+"这些数据的平均值为"+(sum/m));
        scanner.close();
    }
}