格林模拟试题二参考答案

It ought to be fairly intuitive that a component ought to be able to have multiple listeners. After all, a text field might want to respond to both the mouse and keyboard

Answer 41)

1) b=m;

3) d =i;

You can assign up the inheritance tree from a child to a parent but not the other way without an explicit casting. A boolean can only ever be assigned a boolean value.

Answer 42)

2) You can obtain a mutually exclusive lock on any object

3) A thread can obtain a mutually exclusive lock on an object by calling a synchronized method on that object.

4) Thread scheduling algorithms are platform dependent

Yes that says dependent and not independent.

Answer 43)

2) Ask for a re-design of the hierarchy with changing the Operating System to a field rather than Class type

This question is about the requirement to understand the difference between the "is-a" and the "has-a" relationship. Where a class is inherited you have to ask if it represents the "is-a" relationship. As the difference between the root and the two children are the operating system you need to ask are Linux and Windows types of computers.The answer is no, they are both types of Operating Systems. So option two represents the best of the options. You might consider having operating system as an interface instead but that is another story.

Answer 44)

1) An inner class may be defined as static

4) An inner class may extend another class