Multiple choice technology

What will be the result of attempting to compile and run the following code? abstract class MineBase { abstract void amethod(); static int i; } public class Mine extends MineBase { public static void main(String argv[]){ int[] ar=new int[5]; for(i=0;i < ar.length;i++) System.out.println(ar[i]); } }

  1. a sequence of 5 0's will be printed

  2. Error: ar is used before it is initialized

  3. Error Mine must be declared abstract

  4. IndexOutOfBoundes Error
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Mine extends abstract class MineBase but doesn't implement the abstract method amethod(). Therefore Mine must also be declared abstract. If a class doesn't implement all abstract methods from its parent, it must be abstract.

AI explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) A sequence of 5 0's will be printed - This option is incorrect. The code initializes an integer array ar but does not assign any values to its elements. Therefore, the default value of each element in the array will be 0. However, since the amethod() method is not implemented in the Mine class, it cannot be instantiated. Hence, the main() method cannot be executed, and nothing will be printed.

Option B) Error: ar is used before it is initialized - This option is incorrect. The code properly initializes the ar array before using it in the for loop. Therefore, there will be no error related to using ar before initialization.

Option C) Error: Mine must be declared abstract - This option is correct. The Mine class extends the MineBase abstract class, which means it should implement all the abstract methods defined in the abstract class. However, the amethod() method is not implemented in the Mine class. Therefore, if you attempt to compile and run this code, you will receive an error stating that the Mine class must be declared abstract.

Option D) IndexOutOfBoundsException Error - This option is incorrect. The code does not involve any index operations that could result in an IndexOutOfBoundsException.

The correct answer is C. This option is correct because the Mine class does not implement the abstract method amethod(), so it must be declared as an abstract class.

Keep practicing — related questions