实例：判断客户是否中奖与纸牌互换，计算银行本息

一，判断客户是否中奖

package com.Bd22HomeWork12_25;

import java.util.Scanner;

public class Win2 {
    public static void main(String[] args) {
    System.out.println("请输入4位会员卡号：");
    Scanner sc =new Scanner(System.in);//声明创建Scan对象
    int num ;//定义一个四位数数值
    num =  sc.nextInt();//sc数值赋值给num
    System.out.println("会员卡号是"+num);
    int qianwei = num/1000;//求千位数值
    System.out.print("千位数："+qianwei+"	");
    int baiwei = num/100%10;//求百位数值
    System.out.print("百位数："+baiwei+"	");
    int shiwei = num/10%10;//求十位数值
    System.out.print("十位数:"+shiwei+"	");
    int gewei = num%10;//求各位数值
    System.out.println("个位数:"+gewei);
    int sum = qianwei+baiwei+shiwei+gewei;//各位数求和
    System.out.println("会员卡号"+num+"各位数之和："+sum);//输出各位数和
    String isTrue = sum>20?"会员卡号"+num+"的会员，您中奖了！奖品是MP3!":"会员卡号"+num+"的会员，很遗憾，您没有中奖！";//判断
    System.out.println(isTrue);//输出结果
    }
}

结果如图

二，纸牌互换

package com.Bd22HomeWork12_25;

import java.util.Scanner;

public class Change {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();
        System.out.println("输出互换前手中的牌");
        System.out.println("左手中的牌："+a);
        System.out.println("右手中的牌："+b);
        int c = a;
        a = b;
        b = c;
        System.out.println("输出互换后手中的牌");
        System.out.println("左手中的牌："+a);
        System.out.println("右手中的牌："+b);
    }
}

结果如图

三.计算银行本金

package com.Bd22HomeWork12_25;

import java.util.Scanner;

public class Sum {
    public static void main(String[] args) {
        System.out.println("请输入本金：");
        Scanner sc = new Scanner(System.in);
        double money = sc.nextInt();
        System.out.println("本金为："+money);
        double oneYear = money*1.0225;
        double twoYear = money*1.027;
        double threeYear = money*1.0324;
        double fiveYear = money*1.036;
        System.out.println("存取一年后的本息是："+oneYear);
        System.out.println("存取两年后的本息是"+twoYear);
        System.out.println("存取三年后的本息是"+threeYear);
        System.out.println("存取五年后的本息是"+fiveYear);
    }
}

结果如图