Generic method return type
Here's the Animal class:
public class Animal{
private Map<String,Animal> friends =new HashMap<String,Animal>();
public void addFriend(String name,Animal animal){
friends.put(name,animal);
}
public Animal callFriend(String name)
{return friends.get(name);}}
And here's some code snippet with lots of typecasting:
Mouse jerry =newMouse();
jerry.addFriend("spike",newDog());
jerry.addFriend("quacker",newDuck());
((Dog) jerry.callFriend("spike")).bark();
((Duck) jerry.callFriend("quacker")).quack();
Is there any way I can use generics for the return type to get rid of the typecasting, so that I can say
jerry.callFriend("spike").bark();
jerry.callFriend("quacker").quack();
Here's some initial code with return type conveyed to the method as a parameter that's never used.
public<T extendsAnimal> T callFriend(String name, T unusedTypeObj){return(T)friends.get(name);}
Answer==
public<T extendsAnimal> T callFriend(String name,Class<T> type){return type.cast(friends.get(name));}
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