class Cash {
//你需要书写的代码
}
const cash1 = new Cash(105);
const cash2 = new Cash(66);
const cash3 = cash1.add(cash2);
const cash4 = Cash.add(cash1, cash2);
Console.log(`${cash3}`, `${cash4}`);
//代码输出结果为:1元7角1分 1元7角1分