// balance>=12000 balance = balance+(balance*rate); 有问题，咋改啊？

package chaper1;

import java.math.BigInteger;

public class MoodBan {

public static void main(String[] args) {
    // TODO Auto-generated method stub
   BigInteger balance= new BigInteger("10000");
   double rate = 0.03;
   int years = 0;
   while ( balance>=12000) {
       balance = balance+(balance*rate);
       years++;
       System.out.printf("%d年之后，账户本金：%f\n",years,balance);
}
   System.out.println("存款"+years+"后，账户本金超过12000！！");
}

}


double balance = 10000;
        double rate = 0.03;
        int years = 0;
        while (balance <= 12000) {
            balance = balance + (balance * rate);
            years++;
            System.out.printf("%d年之后，账户本金：%f\n", years, balance);
        }
        System.out.println("存款" + years + "后，账户本金超过12000！！");

balance=10000，小于12000，进不了循环呀。

   while ( balance>=12000) {
应该改为
   while ( balance<=12000) {

balance 是10000
while 循环条件( balance>=12000)一开始就不成立,一次也不会循环
应该是 while ( balance<=12000) {吧, >= 改成 <=

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