java - 为什么现在要从我的类中创建对象

Question

当我尝试编译此程序时，错误指向“new”一词。我正在尝试从 carOrder 类创建 2 个对象，但遇到了麻烦!我以前在其他程序中也遇到过这个问题，我不知道为什么，这让我很苦恼，请帮忙!

import java.text.DecimalFormat;
import java.util.Scanner;

public class CarOrder
private String buyer;
private String carType;
private double cost;
private int quantity;
private boolean taxStatus;
private double discountedCost;
private double taxAmount;

// Default Constructor
public void carOrder()
{
}

// Constructor
public void CarOrder(String buy, String car, double cos, int quan, boolean tax)
{
    buyer = buy;
    carType = car;
    cost = cos;
    quantity = quan;
    taxStatus = tax;
}

// Sets the company buying cars
public void setBuyer(String buy)
{
    buyer = buy;
}

// Sets the car type being purchased
public void setCarType(String car)
{
    carType = car;
}

// Sets cost of the cars being purchased
public void setCost(double cos)
{
    cost = cos;
}

// Sets the quantity of cars being purchased
public void setQuantity(int quan)
{
    quantity = quan;
}

// Sets tax status for the cars
public void setTaxStatus(boolean tax)
{
    taxStatus = tax;
}

// Returns name of buyer to user
public String getBuyer()
{
    return buyer;
}

// Returns type of car to user
public String getCarType()
{
    return carType;
}

// Returns cost to user
public double getCost()
{
    return cost;
}

// Returns quantity of cars to user
public int getQuantity()
{
    return quantity;
}

// Returns tax status to user
public boolean getTaxStatus()
{
    return taxStatus;
}

// Returns discounted cost to user
public double getDiscountedCost()
{
    if (quantity > 10)
        if (quantity > 20)
            discountedCost = cost - cost * .10;
        else
            discountedCost = cost - cost * .05;
    else
        discountedCost = cost;

    return discountedCost; 
}

// Returns tax amount to users
public double getTaxAmount()
{
    taxAmount = cost * .0625;
    return taxAmount;
}

public static void main(String[] args)
{
    Scanner keyboard = new Scanner(System.in);
    CarOrder speedy = new CarOrder("Speedy Rental", "Mini Cooper", 22150, 15, true);
    CarOrder zip = new CarOrder("Zip Car Co.", "Ford Fusion", 27495, 6, true);

    System.out.println("Enter first Buyer");
    String buyer1 = keyboard.nextLine();
}

}

Answer 1

public void CarOrder(String buy, String car, double cos, int quan, boolean tax)
{

应该是

public CarOrder(String buy, String car, double cos, int quan, boolean tax)
{

Constructor's don't have a return type, not even void.

目前，您的类中有一个名为 CarOrder 的方法，因为它的返回类型为 void，这违反了 custructor 的规则。如果删除 void，那么它就是一个构造函数，因为它与您的类具有相同的名称。

这同样适用于带有 no-argsaswell 的构造函数。

public void CarOrder()

应该是

public  CarOrder()