**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("請輸入密碼");
        if (scanner.hasNextLine()){
            String str =scanner.nextLine();
            System.out.println("輸出的內容為："+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("請輸入整數：");
        if (scanner.hasNextInt()){
            i =scanner.nextInt();
            System.out.println("輸出的資料為整數"+i);
        }else{
            System.out.println("輸出的資料不是整數");
        }
        System.out.println("請輸入小數：");
        if (scanner.hasNextFloat()){
            f =scanner.nextFloat();
            System.out.println("輸出的資料為小數"+f);
        }else{
            System.out.println("輸出的資料不為小數" );
        }
        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("請輸入資料");
        while (scanner.hasNextDouble()){
            double x = scanner.nextDouble();
            m = m +1 ;
            sum =sum +x;
            System.out.println("你輸入了第"+m+"個數據，這些資料的總和為sum="+sum);
            System.out.println("這些資料的平均值為"+(sum/m));
        }
        System.out.println(m+"這些資料的總和為"+sum);
        System.out.println(m+"這些資料的平均值為"+(sum/m));
        scanner.close();
    }
}