Multiple choice technology web technology

class command { public static void main (String[] a1) { System.out.println(a1.length()); //1 System.out.println(a1[0]); //2 System.out.println(a1); //3 //2 }}

  1. compile time error at line1

  2. compile time error at line2

  3. compile time error at line3

  4. Runtime exception
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In Java, arrays have a length property (not a method). Line 1 attempts to call a1.length() which is a compile-time error because arrays don't have a length() method - they use the length property. Strings have length() method, but arrays use length directly. Option A correctly identifies this compile-time error.

AI explanation

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

Option A) compile time error at line 1 - This option is correct because the code tries to call the length method on the a1 array, which is incorrect. In Java, arrays do not have a length() method. Instead, the length of an array can be accessed using the length field without parentheses. Therefore, there will be a compile-time error at line 1.

Option B) compile time error at line 2 - This option is incorrect. The code correctly accesses the first element of the a1 array using the index 0.

Option C) compile time error at line 3 - This option is incorrect. The code correctly prints the reference to the a1 array.

Option D) Runtime exception - This option is incorrect. There are no runtime exceptions in the given code.

The correct answer is A) compile time error at line 1. This option is correct because the code tries to call the length method on the a1 array, which is incorrect. Arrays in Java do not have a length() method.

Keep practicing — related questions