java - 解决在 Java 中创建构造函数时出现的括号错误

Question

当我尝试在以下程序中打开第二个构造函数时，我在 Eclipse 中遇到括号错误(第 15 行和第 18 行)“public Account myCustomAccount ... Balance = initial Balance; }”。该程序适用于 Dietel“编程入门”第 9 章练习 7。

我怀疑我错误地创建了构造函数。您有什么建议？ (提前谢谢您!!)

import java.util.Date;

public class Account {

//declare required variables
private int id = 0;
private double balance = 0;
private double annualInterestRate = 0; //assume all accounts have the same interest rate
private Date dateCreated = new Date(); //no-argument instance stores the present date


//define default & custom constructors
public Account mydefaultaccount = new Account(); //no-argument instance of Account  

public Account myCustomAccount = new Account(int identNum, double initialBalance) {
    id = identNum;
    balance = initialBalance;
}

//define getters
public int getId() {
    return id;
}

public double getBalance() {
    return balance;
}

public double annualInterestRate() {
    return annualInterestRate;
}

public Date getDate() {
    return dateCreated;
}

//define setters
public void setId(int idSetter) {
    id = idSetter;
}

public void setBalance(double balanceSetter) {
    balance = balanceSetter;
}

public void setAnnualInterestRate(double annualSetter) {
    annualInterestRate = annualSetter;
}

//define required monthly interest rate getter
public double getMonthlyInterestRate() {
    double moInt = annualInterestRate / 12;
    return moInt;
}

//define modifiers
public double withdraw(int withdraw) {
    balance = balance - withdraw;
}

public double deposit(int deposit) {
    balance = balance + deposit;
}
}

Answer 1

这不是定义构造函数的方式。构造函数应遵循以下形式:

public className(parameters) {}

然后，要实例化该类，请调用:

ClassName variable = new ClassName(Parameters);

就您而言，

public Account() {
    /* Body */
}

public Account(int identNum, double initialBalance) {
    /* Body */
} 

并实例化，

Account ac = new Account(Parameters);