Nested Control Structures Challenge Quiz Quiz

Explore your understanding of nested loops, conditionals, and their interactions in programming with this focused quiz. Assess your ability to analyze logic and flow through realistic nested structure scenarios.

1. Nested If-Else Logic

   Given the code snippet: if (x u003E 5) { if (x u003C 10) { y = 1; } else { y = 2; } } else { y = 3; }, what is the value of y if x equals 12?

   1. 12
   2. 3
   3. 2
   4. 1

   Explanation: If x is 12, the first condition (x u003E 5) is true, so the inner if-statement is checked; since 12 is not less than 10, the program executes y = 2. Option 1 is incorrect because it only happens when x is greater than 5 but less than 10. Option 3 applies when x is 5 or less, which is not the case. Option 12 confuses the variable assignment with the value of x. Only option 2 matches the logic flow.

2. Counting Nested Loops Iterations

   In the pseudocode 'for i from 1 to 3 { for j from 1 to 2 { print(i, j) } }', how many times will the print statement execute?

   1. 6
   2. 5
   3. 9
   4. 3

   Explanation: The outer loop runs 3 times and for each iteration, the inner loop runs 2 times, resulting in 3 multiplied by 2, which is 6 iterations. Option 5 is close but not correct as it understates the total. Option 3 represents only the outer loop iterations, and option 9 overestimates by multiplying incorrect loop bounds. Six is the correct answer.

3. Understanding Loop Control Flow

   What is the output after executing this pseudocode: for x from 1 to 4 { if (x % 2 == 0) { continue } print(x) }?

   1. 2 4
   2. 3 4
   3. 1 2 3 4
   4. 1 3

   Explanation: The 'continue' statement skips to the next iteration when x is even, so only odd numbers 1 and 3 are printed. Option 2 lists only the even numbers, which are skipped. Option 1 suggests all numbers are printed, ignoring the conditional logic. Option 4 begins from 3 instead of considering the starting value. Only option 3 fits the intended loop control.

4. Effect of Nested Loops on Variable Values

   Suppose: int total = 0; for a from 1 to 2 { for b from 1 to 3 { total++ } }, what is the value of total after the loops finish?

   1. 6
   2. 3
   3. 5
   4. 4

   Explanation: The outer loop runs twice, and for each, the inner loop runs three times, leading to 2 times 3 equals 6 increments of 'total'. Option 5 undercounts the iterations, option 3 only considers the inner loop, and option 4 miscalculates the total. Option 6 correctly represents the end value of 'total' after all iterations.

5. Conditional Statements Within Loops

   Given: for i from 1 to 4 { if (i == 2 || i == 4) { print('A') } else { print('B') } }, what is the printed sequence?

   1. AAAB
   2. BBAA
   3. ABAB
   4. BABA

   Explanation: On iterations where i equals 2 or 4, 'A' is printed; otherwise, 'B' is printed. This results in the sequence 'B' (i=1), 'A' (i=2), 'B' (i=3), 'A' (i=4). Option AAAB does not match any logical sequence from the code, BBAA and ABAB mix up the pattern, leaving only BABA as the correct answer. Each option shows a possible pattern, but only BABA reflects the described logic.