Given: 

1. enum A { A } 
2. class E2 { 
3.   enum B { B } 
4.   void C() { 
5.     enum D { D } 
6.   } 
7. }

Which statements are true? (Choose all that apply.)

technology programming languages

  1. If only line 1 is removed the code compiles.

  2. If only line 3 is removed the code compiles.

  3. If only line 5 is removed the code compiles.

  4. If lines 1 and 3 are removed the code compiles

  5. If lines 1, 3 and 5 are removed the code compiles.

Show answer
Correct Option: C,E

AI Explanation

To answer this question, we need to understand the rules and restrictions regarding the declaration and usage of enums in Java.

In Java, an enum is a special data type that allows for a variable to be a set of predefined constants. Each constant is defined within the enum. Enums can only be declared at the top level of a class or interface, or within a class (as a member) but not inside a method.

Let's go through each option to understand why it is correct or incorrect:

Option A) If only line 1 is removed the code compiles. This option is incorrect because removing line 1 would remove the declaration of enum A. Since enum A is not used in the code, its removal does not affect the compilation.

Option B) If only line 3 is removed the code compiles. This option is incorrect because removing line 3 would remove the declaration of enum B. However, enum B is used within the class E2, so its removal would result in a compilation error.

Option C) If only line 5 is removed the code compiles. This option is correct because removing line 5 would remove the declaration of enum D, which is a local enum declared inside the method C(). Since enum D is not used outside of the method, its removal does not affect the compilation.

Option D) If lines 1 and 3 are removed the code compiles. This option is incorrect because removing line 1 would remove the declaration of enum A, and removing line 3 would remove the declaration of enum B. Since enum B is used within the class E2, its removal would result in a compilation error.

Option E) If lines 1, 3, and 5 are removed the code compiles. This option is correct because removing line 1 would remove the declaration of enum A, removing line 3 would remove the declaration of enum B, and removing line 5 would remove the declaration of enum D. Since enum B is used within the class E2, its removal would result in a compilation error. However, since enum D is a local enum declared inside the method C(), its removal does not affect the compilation.

Therefore, the correct answer is: C. If only line 5 is removed the code compiles. E. If lines 1, 3, and 5 are removed the code compiles.

Find more quizzes: