c++ - C++，Visual Studio 2019，类错误，变量是非标准语法

Question

我正在寻求帮助以完成此代码，我需要它在初始余额减少 5 倍 10% 后输出两个支票账户的信息。我设置了一个 for 循环，我认为它可以循环 newbalance 的实例方法，但是当我成功运行循环时，它打印出 10% 的减少 5 次，而不是运行公式 5 次。当我尝试打印数据（例如名字、姓氏和新帐户余额）时，我收到一条错误消息，指出非标准语法，请使用 & 创建指针。不知道如何解决这个问题，这也会影响 firstName 和 lastName 的字符串变量。

include <string>
include <iostream>
include <cmath>
using namespace std;
class CheckingAccount {

public:
CheckingAccount(string, string, double);
void setbalance(double b) {
    balance = b; 
}

double getbalance() {
    return balance;
}
void setfirstName(string f) {
    firstName = f;
}
string getfirstName() {
    return firstName;
}
void setlastName(string l) {
    lastName = l;
}
string getlastName() {
    return lastName;
}

double newbalance() {
return(balance * .9);
}

private:
string firstName;
string lastName;
double balance;

};
CheckingAccount::CheckingAccount(string x, string y, double z) {
firstName = x;
lastName = y;
balance = z;
}

int main()
 {

CheckingAccount account1("Daniel", "Longo", 500);
CheckingAccount account2("Joe", "Mam", 750);

int i;
for (i = 0; i < 5; i++) {
     account1.newbalance();
     account2.newbalance();
}
cout << account1.getfirstName << " " << account1.getlastName << " now 
has $"
    << account1.newbalance() << " in their account." << endl;
cout << account2.getfirstName << " " << account2.getlastName << " now 
has $"
    << account2.newbalance() << " in their account." << endl;
}

任何有关如何修复此问题的想法将不胜感激！

标签： c++class