Class 9 Nested Loops Mock Test (ICSE)

Topics in Nested Loops

• Nested for loops
• Patterns using nested loops
• Series using nested loops
• Labelled break and continue

Nested Loops practice questions with answers

1. Q1Multiple choice·1 mark
   Which nested loop structure is appropriate for finding the sum of the series: $S = 1! + 2! + 3! + \dots + n!$?

   1. (a)An inner loop running up to $n$ for every term and an outer loop adding each result to the sum.
   2. (b)A factorial variable set to 1 once before both loops, multiplied by the inner loop for each term.
   3. (c)An inner loop to compute factorial and an outer loop that resets the sum to 0 for each term.
   4. (d)An inner loop to compute factorial and an outer loop to accumulate the sum up to $n$.
   Show answer and step marks

   1. Correct option: (d) An inner loop to compute factorial and an outer loop to accumulate the sum up to $n$.+1

   Answer: (d)
2. Q2Assertion and reason·1 mark
   Assertion (A): A labelled break can exit an outer loop from inside an inner loop. Reason (R): A plain break only terminates the innermost loop that contains it.

   1. (a)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
   2. (b)Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
   3. (c)Assertion (A) is true but Reason (R) is false.
   4. (d)Assertion (A) is false but Reason (R) is true.
   Show answer and step marks

   1. Correct option: (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).+1

   Answer: (a)
3. Q3Multiple choice·1 mark
   In a nested loop used to print a right-angled triangle pattern of numbers where the row number dictates the number of columns, the outer loop typically controls:

   1. (a)the termination condition of the inner loop directly
   2. (b)the number of rows in the pattern
   3. (c)the number of columns in each row
   4. (d)the spacing between characters
   Show answer and step marks

   1. Correct option: (b) the number of rows in the pattern+1

   Answer: (b)
4. Q4Short answer·2 marks
   Explain the purpose of a labelled continue statement in Java. Provide a brief illustrative syntax.
   Show answer and step marks

   1. State that a labelled continue skips the remaining statements of the current iteration of the specified outer loop and proceeds to its next iteration.+1
   2. Provide correct syntax usage: outer: for(...) { for(...) { continue outer; } }+1

   Answer: A labelled continue skips the rest of the current iteration of the labelled (outer) loop and continues with that loop's next iteration. Syntax: outer: for (int i = 1; i ≤ 3; i++) { for (int j = 1; j ≤ 3; j++) { if (j == 2) continue outer; System.out.println(i + " " + j); } }
5. Q5Short answer·3 marks
   Study the Java code fragment below and write the exact output it prints. Write each line of output on a separate line. for (int i = 1; i ≤ 4; i++) { for (int j = 4; j ≥ i; j--) { System.out.print(j); } System.out.println(); }
   Show answer and step marks

   1. Row 1: i = 1, so j runs from 4 down to 1, printing 4, 3, 2, 1, giving 4321+0.5
   2. Row 2: i = 2, so j runs from 4 down to 2, printing 4, 3, 2, giving 432+0.5
   3. Row 3: i = 3, so j runs from 4 down to 3, printing 43+1
   4. Row 4: i = 4, so j runs from 4 down to 4, printing 4+1

   Answer: 4321 432 43 4
6. Q6Long answer·4 marks
   Write a program in Java using nested for loops to display the following triangular pattern: 1 2 4 3 6 9 4 8 12 16
   Show answer and step marks

   1. Correct class declaration and main method structure.+0.5
   2. Outer loop for the rows: for (int i = 1; i ≤ 4; i++).+1
   3. Inner loop for the columns: for (int j = 1; j ≤ i; j++).+1
   4. Inside the inner loop, print the product with a space: System.out.print(i × j + " ");+1
   5. System.out.println(); after the inner loop to move to the next row.+0.5

   Answer: public class Pattern { public static void main(String[] args) { for (int i = 1; i ≤ 4; i++) { for (int j = 1; j ≤ i; j++) { System.out.print(i × j + " "); } System.out.println(); } } } Output: 1 2 4 3 6 9 4 8 12 16

More Class 9 Computer Applications mock tests