java - 在java中使用对象函数

Question

我正在尝试用 Java 实现函数对象。我有一个 Unit 类，它有一个默认的加法函数，应该在 Unit 对象的大多数初始化中使用。但是，对于某些问题，我需要一个不同的加法函数。代码看起来像这样:

public class Unit() {
   public Unit(unitType) {
      if (unitType == "specialType") {
         additionFunc = defaultFunc } else {
         additionFunc = specialFunc }
      }
   }
   public int swim() {
      return additionFunc()
   }
  // definiion of regularFunc
  // definition of specialFunc

}

然后，从主文件:

Unit fish = new Unit(regularTyoe);
Unit fatFish = new Unit(specialType);
fish.swim(); //regular function is called
fatFish.swim(); //special function is called

就是这样......有谁知道如何做到这一点？

Answer 1

你需要查找inheritance和 method overriding .阅读适当的面向对象编程也可能会有所帮助。

正确的做法是:

class Fish {
  public void swim() {
    // normal swim
  }
}

class FatFish extends Fish {
  @Override
  public void swim() {
    // special swim
  }
}

Fish fish = new Fish()
Fish fatFish = new FatFish()
fish.swim()    // normal swim
fatFish.swim() // slow swim