银行存取款系统（附带理财）
import java.util.Scanner;
public class Atmm{
public static void main(String[]args){
//1初始化模块
int password=123456;
double balance=10000.00;
Scanner scanner=new Scanner(System.in);
//scanner扫描意思
//2循环加判断
boolean b=false; //做标识
for(int i=0;i<3;i++){
System.out.println("input password");
int input=scanner.nextInt(); //接受用户输入密码
if(input==password){
b=true;
break;
}else{
System.out.println("error");
}
}
//3
if(b){
loop:while(true){
System.out.println("pelase select ");
System.out.println("1\t show balance"); //1代表余额
System.out.println("2\t draw");
System.out.println("3\t save");
System.out.println("4\t exit");
int input=scanner.nextInt();
switch(input){
case 1:
System.out.println("you balance \t"+balance);
System.out.println("do you want to licai");
System.out.println("1 \tyes");
System.out.println("2 \tno");
int input1=scanner.nextInt();
switch(input1){
case 1:
System.out.println("you licai");
System.out.println("1\t jijin (0.03)");
System.out.println("2\tzhaiquan (0.04)");
System.out.println("3\tdingqi (0.02)");
int input2=scanner.nextInt();
switch(input2){
case 1:
System.out.println("Amount deposited in the fund");
double a3=scanner.nextDouble();
if(a3>0&&a3<balance)
{
System.out.println("How many years do you want to save? ");
int year=scanner.nextInt();
balance-=a3;
double a4=a3*(0.03)*year+a3;
System.out.println("Account balance :"+balance );
System.out.println("Estimated revenue:"+a4);
}
else System.out.println( "Input amount error");
break;
//输入钱数大于0小于余额，询问年数，计算剩余存款和预计收益
case 2:
System.out.println("Amount deposited in bonds");
double a5=scanner.nextDouble();
if(a5>0&&a5<balance)
{
System.out.println("How many years do you want to save?");
int year=scanner.nextInt();
balance-=a5;
double a6=a5*(0.04)*year+a5;
System.out.println("Account balance:"+balance);
System.out.println("Estimated revenue:"+a6);
}
else System.out.println("Input amount error");break loop;
case 3:
System.out.println("Time Deposit Amount");
double a7=scanner.nextDouble();
if(a7>0&&a7<balance)
{
System.out.println("How many years do you want to save?");
int year=scanner.nextInt();
balance-=a7;
double a8=a7*(0.02)*year+a7;
System.out.println("Account balance:"+balance);
System.out.println("Estimated revenue:"+a8);
}
else System.out.println("Input amount error");break loop;
}
case 2: break loop;
}
case 2:
System.out.println("input money");
double money1=scanner.nextDouble();
if(money1>0&&money1<=balance){
balance -= money1;
System.out.println("ok="+balance);
}else{
System.out.println("error");
}
break;
case 3:
System.out.println("input money");
double money2=scanner.nextDouble();
if(money2>0){
balance+=money2;
System.out.println("ok="+balance);
}else{
System.out.println("error");
}
break;
case 4: break loop;
default:
System.out.println("error");
break;
}
}
}
//4
scanner.close();
System.out.println("bye!");
}
}
算数运算符：
+ 加运算
- 减运算
* 乘运算
/ 除运算
% 取余数
++a 用变量a之前，先使a的值加1
a++ 用变量a之后，使a的值加1
（举例：a=2；b=a++；运行结果 b=2，a=3 a=2；b=++a； 运行结果 b=3，a=3）
> 大于
< 小于
== 等于
>= 大于等于
<= 小于等于
!= 不等于
&& 与 短路
& 与 不短路
类型转换
int类型不能转为byte类型，byte可以转为int类型
变量=（变量类型）值
两个值参与运算，会发生自动类型的提升 强转
例： byte a=1;byte b=2;byte c=(byte)(a+b)
三元运算符 条件式？值1：值2
（例：若条件式的值为true，则整个表达式取值1，否则取值2 Boolean b = 20 >45?true:false;）
