Java认证模考试题（七）

文章作者 100test 发表时间 2007:03:14 17:02:45
来源 100Test.Com百考试题网

Question: 38

The Person, Student and Teacher are class names. These classes have the following inheritance relation as shown below:

Person

|

---------------

| |

Student Teacher

There is the following expression in a Java source file:

Person p = new Teacher().

Which of the following expressions return true?

A. p instanceof Teacher

B. p instanceof Student

C. p instanceof Person

D. None of them returns true

Explanation:

The instanceof operator is used to test the type of an object. Because the reference p refers to a Teacher object and the Teacher is a subclass of the Person class the expressions in answer A and C will return true.

Correct Answer: A,C 38 of 60