java - 如何在 java 子类中添加两个变量以作为一个变量传递给父类(super class)？

Question

我正在学习Java，我有一个问题。我不确定我使用的术语是否正确，因此如有必要，请纠正我。我很好奇是否有更好的方法来添加前爪和后爪以将它们传递给 Animal 类。这是按原样工作的，但我在搜索我想要做的事情时遇到了困难，这使得很难弄清楚我是否做错了。这是我正在使用的子类。

public class Bear extends Animal // This is a Bear class, it is a subclass of Animal.
{
  private int frontClaws; // This is an instance variable for front claws.
  private int backClaws;  // This is an instance variable for back claws.
  public Bear (String name, int fC, int bC) // This is the Bear constructor.
  {
    super (name, fC + bC); // This passes the name and the sum 
                           // of the claws to the Animal's constructor

    frontClaws = fC;  // not sure why this has to be done, 
                      // and frontClaws + backClaws can't be used directly. Because they are private?
    backClaws = bC;   // Same as confusion as above.
   }
    public void print()  // This calls the print method.
   {
    super.print();    // This calls the print method from 
                      // Animal and prints the args from Animal 
                      // as well as the args from Bear.
    System.out.println("- " + frontClaws + " Front Claws, and " + backClaws + " Back Claws.");
   }
}

提前致谢!

tc

Answer 1

在调用父类(super class)构造函数之前，您无法访问字段 - 基本上，任何构造函数所做的第一件事就是调用父类(super class)构造函数。您要做的唯一一件事就是评估参数以调用该父类(super class)构造函数 - 在您的情况下，这涉及将 fC 和 bC 相加。

基本上，假设您需要 Animal 来获得 frontClaws 和 backClaws 的总和，这看起来像合理实现。