Multiple choice technology databases

What is the value of l_child_number? DECLARE l_parent_number NUMBER := 1; BEGIN DECLARE l_child_number NUMBER := 2; BEGIN l_child_number := l_parent_number + l_child_number; END; DBMS_OUTPUT.PUT_LINE(TO_CHAR(l_child_number)); EXCEPTION WHEN OTHERS THEN l_child_number := 0; DBMS_OUTPUT.PUT_LINE(TO_CHAR(l_child_number); END;

  1. 1

  2. 2

  3. 3

  4. 0

  5. None of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The variable l_child_number is declared in the inner DECLARE block with scope limited to that block. When DBMS_OUTPUT.PUT_LINE in the outer block tries to access l_child_number, the variable is out of scope, causing an exception. The WHEN OTHERS exception handler sets l_child_number to 0, so the output is 0. This tests understanding of PL/SQL variable scope.

AI explanation

To determine the value of l_child_number, let's go through the code step by step:

  1. The variable l_parent_number is declared and assigned a value of 1.
  2. Inside the outer BEGIN block, the variable l_child_number is declared and assigned a value of 2.
  3. Inside the inner BEGIN block, l_child_number is updated by adding l_parent_number and l_child_number. Therefore, l_child_number becomes 1 + 2 = 3.
  4. After the inner BEGIN block, the value of l_child_number is printed using DBMS_OUTPUT.PUT_LINE.
  5. If any exception occurs in the code, the WHEN OTHERS block is executed, and l_child_number is assigned a value of 0.
  6. Since there are no exceptions in the code, the value of l_child_number remains 3, and it is printed.

Therefore, the correct answer is D) 0.

Keep practicing — related questions