BlueJ Java问题

我的冰淇淋项目有些问题

当我使用topping和ice cream类中的访问器方法返回字符串值时，它们不会返回字符串值。我没有注意到代码有任何问题

当我进入圣代课程，输入冰淇淋的细节并加满时，它会出现这样的信息。​

错误：不兼容的类型：java.lang.String无法转换为冰淇淋

以下是冰淇淋、配料和圣代类的代码：

IceCream.java Topping.java 圣代java

---

感谢您的帮助

您的代码中有一些错误

1。您的实例变量未在上述所有类中正确初始化。

public String getDetails() // Sundae class
{       
    return scoops + " scoops of " + typeOfScoop + " Ice Cream" +  " with " + typeOfTopping + " with a price of " + getPrice();
}

IceCream类中的构造函数可能应该是：

public IceCream(String typeOfScoop)
{
    // initialise instance variables
       this.typeOfScoop = typeOfScoop;
       price = 1.20;
}

public Topping(String typeOfTopping)
{
   // initialise instance variables
      this.typeOfTopping = typeOfTopping;
      price = 0.40;
}

public Sundae(IceCream scoopType, Topping typeOfTopping, int scoops)
{
   // initialise instance variables     
      this.typeOfScoop = scoopType;
      this.typeOfTopping = typeOfTopping;
      this.scoops = scoops;
}

public void setScoopType (String typeOfScoop)
{
     this.typeOfScoop = typeOfScoop;
}

public void setTopping(String typeOfTopping)
{
     this.typeOfTopping = typeOfTopping;
}

Topping类中的构造函数可能是：

public IceCream(String typeOfScoop)
{
    // initialise instance variables
       this.typeOfScoop = typeOfScoop;
       price = 1.20;
}

public Topping(String typeOfTopping)
{
   // initialise instance variables
      this.typeOfTopping = typeOfTopping;
      price = 0.40;
}

public Sundae(IceCream scoopType, Topping typeOfTopping, int scoops)
{
   // initialise instance variables     
      this.typeOfScoop = scoopType;
      this.typeOfTopping = typeOfTopping;
      this.scoops = scoops;
}

public void setScoopType (String typeOfScoop)
{
     this.typeOfScoop = typeOfScoop;
}

public void setTopping(String typeOfTopping)
{
     this.typeOfTopping = typeOfTopping;
}

Sundae类中的构造函数可能是：

public IceCream(String typeOfScoop)
{
    // initialise instance variables
       this.typeOfScoop = typeOfScoop;
       price = 1.20;
}

public Topping(String typeOfTopping)
{
   // initialise instance variables
      this.typeOfTopping = typeOfTopping;
      price = 0.40;
}

public Sundae(IceCream scoopType, Topping typeOfTopping, int scoops)
{
   // initialise instance variables     
      this.typeOfScoop = scoopType;
      this.typeOfTopping = typeOfTopping;
      this.scoops = scoops;
}

public void setScoopType (String typeOfScoop)
{
     this.typeOfScoop = typeOfScoop;
}

public void setTopping(String typeOfTopping)
{
     this.typeOfTopping = typeOfTopping;
}

2。不正确的突变方法。

public String getDetails() // Sundae class
{       
    return scoops + " scoops of " + typeOfScoop + " Ice Cream" +  " with " + typeOfTopping + " with a price of " + getPrice();
}

IceCream类中正确的mutator方法可能是：

public IceCream(String typeOfScoop)
{
    // initialise instance variables
       this.typeOfScoop = typeOfScoop;
       price = 1.20;
}

public Topping(String typeOfTopping)
{
   // initialise instance variables
      this.typeOfTopping = typeOfTopping;
      price = 0.40;
}

public Sundae(IceCream scoopType, Topping typeOfTopping, int scoops)
{
   // initialise instance variables     
      this.typeOfScoop = scoopType;
      this.typeOfTopping = typeOfTopping;
      this.scoops = scoops;
}

public void setScoopType (String typeOfScoop)
{
     this.typeOfScoop = typeOfScoop;
}

public void setTopping(String typeOfTopping)
{
     this.typeOfTopping = typeOfTopping;
}

Topping类中正确的mutator方法可能是：

public IceCream(String typeOfScoop)
{
    // initialise instance variables
       this.typeOfScoop = typeOfScoop;
       price = 1.20;
}

public Topping(String typeOfTopping)
{
   // initialise instance variables
      this.typeOfTopping = typeOfTopping;
      price = 0.40;
}

public Sundae(IceCream scoopType, Topping typeOfTopping, int scoops)
{
   // initialise instance variables     
      this.typeOfScoop = scoopType;
      this.typeOfTopping = typeOfTopping;
      this.scoops = scoops;
}

public void setScoopType (String typeOfScoop)
{
     this.typeOfScoop = typeOfScoop;
}

public void setTopping(String typeOfTopping)
{
     this.typeOfTopping = typeOfTopping;
}

3。对象到字符串的转换不正确。

public String getDetails() // Sundae class
{       
    return scoops + " scoops of " + typeOfScoop + " Ice Cream" +  " with " + typeOfTopping + " with a price of " + getPrice();
}

typeOfScoop和TypeOfTaping变量不是字符串。Java无法在上述方法中将它们自动转换为所需的字符串，因为您没有重写IceCream和Topping类中的toString（）方法

必须添加以下两种方法：

把这个加到冰淇淋课上

@Override
public String toString() 
{       
    return typeOfScoop;
}

将此添加到Topping类

@Override
public String toString() 
{       
   return typeOfTopping;
}

或将Sundae类中的getDetails（）方法修改为：

public String getDetails()
{   
   return scoops + " scoops of " + typeOfScoop.getScoopType() + " Ice Cream" +  " with " + typeOfTopping.getTopping() + " with a price of " + getPrice();
}

希望这能有所帮助。祝你好运，编程愉快

干杯

---

崇高的

你的主要职业在哪里？@polywhill先生：这个问题在我看来已经足够明显了，不需要

Main

。所以这是一个？…这段代码中有很多奇怪的事情：在

冰淇淋：：setcooptype

和

Topping：：setTopping

中缺少

这个

，不要在圣代的构造函数中使用

scoopType

参数。。。打字错误与否？您可以提供

main

条目吗？您的

Sundae

类中有一个错误<代码>this.typeOfScoop=typeOfScoop应该是：

this.typeOfScoop=scoopType非常感谢！这对我帮助很大