在Java中創建構造函數時解決括號錯誤

Question

當我嘗試在以下程序中打開第二個構造函數時，在Eclipse中出現括弧錯誤（第15和18行）“ public Account myCustomAccount ... balance = initial balance;}”。 該程序適用於Dietel“編程入門”第9章練習7。

我懷疑自己在錯誤地創建了構造函數。 您提供什么建議？ （提前謝謝您！！）

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

那不是定義構造函數的方式。 構造函數應遵循以下形式：

public className(parameters) {}

然后，要實例化該類，請調用：

ClassName variable = new ClassName(Parameters);

就你而言

public Account() {
    /* Body */
}

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

並實例化

Account ac = new Account(Parameters);