Looping Constructs (for loop, while loop, ...etc) MCQ

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1. Which looping construct in C is used when the number of iterations is known beforehand?

ⓐ. for loop

ⓑ. while loop

ⓒ. do-while loop

ⓓ. if-else loop

Explanation: The for loop is used when the number of iterations is known beforehand, making it suitable for iterating a specific number of times.

2. In a for loop, what does the initialization expression do?

ⓐ. Defines the loop condition

ⓑ. Executes before each iteration

ⓒ. Executes after each iteration

ⓓ. Initializes loop counter(s)

Explanation: The initialization expression in a for loop is used to initialize loop counter(s) before the loop begins executing.

3. What will be the output of the following code snippet?


int main() {
    int i;
    for(i = 0; i < 5; i++) {
        printf("%d ", i);
    }
    return 0;
}

ⓐ. 0 1 2 3 4

ⓑ. 1 2 3 4 5

ⓒ. 0 1 2 3

ⓓ. 1 2 3 4

Explanation: The loop iterates from i = 0 to i = 4 (inclusive), printing each value of i followed by a space.

4. Which looping construct is guaranteed to execute at least once?

ⓐ. for loop

ⓑ. while loop

ⓒ. do-while loop

ⓓ. if-else loop

Explanation: Unlike the for and while loops, the do-while loop guarantees that the loop body will execute at least once before checking the loop condition.

5. What is the purpose of the continue statement in a loop?

ⓐ. To terminate the loop

ⓑ. To skip the remaining code in the loop and proceed to the next iteration

ⓒ. To restart the loop from the beginning

ⓓ. To print a message and then continue to the next iteration

Explanation: The continue statement is used to skip the remaining code inside the loop and proceed to the next iteration of the loop.

6. Which loop is more suitable when the loop condition depends on user input?

ⓐ. for loop

ⓑ. while loop

ⓒ. do-while loop

ⓓ. switch loop

Explanation: The do-while loop is suitable when the loop condition depends on user input because it guarantees that the loop body will execute at least once.

7. What happens if the loop condition in a while loop is initially false?

ⓐ. The loop executes indefinitely

ⓑ. The loop executes once

ⓒ. The loop does not execute at all

ⓓ. The loop executes until the condition becomes true

Explanation: If the loop condition in a while loop is initially false, the loop body will not execute at all.

8. In a nested loop, which loop's body executes more frequently?

ⓐ. Outer loop

ⓑ. Inner loop

ⓒ. Both execute the same number of times

ⓓ. It depends on the specific conditions

Explanation: In a nested loop, the inner loop's body executes more frequently as it typically iterates through its range multiple times within each iteration of the outer loop.

9. What is the purpose of the break statement in a loop?

ⓐ. To skip the remaining code in the loop and proceed to the next iteration

ⓑ. To restart the loop from the beginning

ⓒ. To terminate the loop prematurely

ⓓ. To print a message and then continue to the next iteration

Explanation: The break statement is used to prematurely terminate the loop and exit its execution.

10. Which loop construct is used when you want the loop to continue indefinitely until a certain condition is met?

ⓐ. for loop

ⓑ. while loop

ⓒ. do-while loop

ⓓ. infinite loop

Explanation: An infinite loop continues indefinitely until explicitly terminated, typically by a break statement or when a specific condition is met.

11. What is the syntax for a for loop in C?

ⓐ. for (initialization; condition; increment/decrement)

ⓑ. for (condition; increment/decrement; initialization)

ⓒ. for (condition; initialization; increment/decrement)

ⓓ. for (increment/decrement; condition; initialization)

Explanation: The correct syntax for a for loop in C is "for (initialization; condition; increment/decrement)".

12. What happens if the increment/decrement expression is omitted in a for loop?

ⓐ. It causes a syntax error

ⓑ. It defaults to incrementing by 1

ⓒ. It defaults to decrementing by 1

ⓓ. It defaults to not incrementing or decrementing

Explanation: If the increment/decrement expression is omitted in a for loop, it defaults to incrementing by 1, effectively acting like "i++".

13. Which of the following is a valid way to terminate a for loop prematurely?

ⓐ. return statement

ⓑ. continue statement

ⓒ. break statement

ⓓ. exit() function

Explanation: The break statement is used to terminate a loop prematurely, regardless of whether it's a for loop, while loop, or do-while loop.

14. What will be the output of the following code snippet?


int main() {
    int i;
    for(i = 0; i < 3; i++) {
        printf("%d ", i);
    }
    return 0;
}

ⓐ. 0 1 2

ⓑ. 1 2 3

ⓒ. 0 1 2 3

ⓓ. 1 2

Explanation: The loop iterates from i = 0 to i = 2 (inclusive), printing each value of i followed by a space.

15. What will be the output of the following code snippet?


int main() {
    int i;
    for(i = 0; i < 5; i += 2) {
        printf("%d ", i);
    }
    return 0;
}

ⓐ. 0 1 2 3 4

ⓑ. 0 2 4

ⓒ. 1 3

ⓓ. 0 2 4 6 8

Explanation: The loop iterates from i = 0 to i = 4 (inclusive), incrementing i by 2 in each iteration, and printing each value of i followed by a space.

16. What is the purpose of the initialization expression in a for loop?

ⓐ. To define the loop condition

ⓑ. To execute before each iteration

ⓒ. To execute after each iteration

ⓓ. To initialize loop counter(s)

Explanation: The initialization expression in a for loop is used to initialize loop counter(s) before the loop begins executing.

17. What is the output of the following code snippet?


int main() {
    int i;
    for(i = 5; i >= 0; i--) {
        printf("%d ", i);
    }
    return 0;
}

ⓐ. 5 4 3 2 1 0

ⓑ. 5 4 3 2 1

ⓒ. 4 3 2 1 0

ⓓ. 5 4 3 2

Explanation: The loop iterates from i = 5 to i = 0 (inclusive), decrementing i by 1 in each iteration, and printing each value of i followed by a space.

18. What happens if the condition in a for loop is initially false?

ⓐ. The loop executes indefinitely

ⓑ. The loop executes once

ⓒ. The loop does not execute at all

ⓓ. The loop executes until the condition becomes true

Explanation: If the condition in a for loop is initially false, the loop body will not execute at all.

19. In a for loop, where is the increment/decrement expression typically placed?

ⓐ. Before the loop condition

ⓑ. After the loop condition

ⓒ. Inside the loop body

ⓓ. It can be placed anywhere within the loop

Explanation: In a for loop, the increment/decrement expression is typically placed after the loop condition.

20. Which of the following statements about the for loop in C is false?

ⓐ. The initialization expression is executed before each iteration.

ⓑ. The condition is evaluated before each iteration.

ⓒ. The increment/decrement expression is executed after each iteration.

ⓓ. The loop body must contain at least one statement.

Explanation: The initialization expression in a for loop is executed only once before the loop begins executing, not before each iteration.

21. What will be the output of the following code snippet?


int main() {
    int i;
    for(i = 0; i < 5; ++i) {
        printf("%d ", i);
        i++;
    }
    return 0;
}

ⓐ. 0 1 2 3 4

ⓑ. 1 2 3 4

ⓒ. 0 2 4

ⓓ. This code will result in an infinite loop

Explanation: Inside the loop, both the printf statement and the i++ statement increment i, resulting in skipping odd numbers.

22. What is the purpose of the comma operator in the initialization expression of a for loop?

ⓐ. To separate multiple conditions

ⓑ. To separate multiple statements

ⓒ. To define a range for iteration

ⓓ. To perform bitwise operations

Explanation: The comma operator in the initialization expression of a for loop is used to separate multiple statements.

23. Which of the following statements about the iteration statement in a for loop is true?

ⓐ. It must always be an incrementation.

ⓑ. It must always be a decrementation.

ⓒ. It can be an incrementation or a decrementation.

ⓓ. It cannot be used within a for loop.

Explanation: The iteration statement in a for loop can be either an incrementation or a decrementation, depending on the requirement of the loop.

24. What is the output of the following code snippet?


int main() {
    int i = 0;
    for(;;) {
        if (i > 3)
            break;
        printf("%d ", i);
        i++;
    }
    return 0;
}

ⓐ. 0 1 2 3

ⓑ. 0 1 2

ⓒ. 1 2 3

ⓓ. This code will result in an infinite loop

Explanation: This code snippet uses an infinite loop with a break statement to terminate the loop when i becomes greater than 3.

25. What is the purpose of using the continue statement in a for loop?

ⓐ. To skip the remaining code in the loop and proceed to the next iteration

ⓑ. To terminate the loop prematurely

ⓒ. To restart the loop from the beginning

ⓓ. To execute the loop body only once

Explanation: The continue statement is used to skip the remaining code in the loop and proceed to the next iteration of the loop.

26. What will be the output of the following code snippet?


int main() {
    int i;
    for(i = 0; i < 5; i++) {
        if (i == 3)
            continue;
        printf("%d ", i);
    }
    return 0;
}

ⓐ. 0 1 2 4

ⓑ. 0 1 2 3 4

ⓒ. 1 2 4

ⓓ. 0 1 2 4 5

Explanation: The continue statement skips the printing of the value when i is equal to 3, resulting in skipping 3 from the output.

27. Which statement about the loop counter in a for loop is true?

ⓐ. It must always be declared inside the loop body.

ⓑ. It must always be declared before the loop.

ⓒ. It can be declared either inside or outside the loop.

ⓓ. It cannot be declared within a for loop.

Explanation: The loop counter in a for loop can be declared either inside the loop initialization or outside the loop body, depending on the requirement.

28. What is the difference between pre-increment (++i) and post-increment (i++) operators in a for loop?

ⓐ. There is no difference; both increment the value of i by 1.

ⓑ. Pre-increment increments the value of i before its current value is used, while post-increment increments it after its current value is used.

ⓒ. Pre-increment increments the value of i after its current value is used, while post-increment increments it before its current value is used.

ⓓ. Pre-increment increments the value of i by 2, while post-increment increments it by 1.

Explanation: Pre-increment (++i) increments the value of i before its current value is used in the expression, while post-increment (i++) increments it after its current value is used.

29. In a nested for loop, how are the loop control variables typically named to avoid confusion?

ⓐ. They must have the same name to maintain consistency.

ⓑ. They must have different names to avoid conflicts.

ⓒ. They should have names based on the iteration level.

ⓓ. They should have names based on their purpose within the loop.

Explanation: In a nested for loop, the loop control variables are typically named based on the iteration level to avoid confusion and maintain clarity in the code.

30. What will be the output of the following code snippet?


int main() {
    int i, j;
    for(i = 0; i < 3; i++) {
        for(j = 0; j < 2; j++) {
            printf("%d,%d ", i, j);
        }
    }
    return 0;
}

ⓐ. 0,0 0,1 1,0 1,1 2,0 2,1

ⓑ. 0,0 1,0 2,0 0,1 1,1 2,1

ⓒ. 0,0 0,1 1,1 1,2 2,0 2,1

ⓓ. 0,0 0,1 1,0 1,1 2,1 2,2

Explanation: This code snippet uses nested for loops to print combinations of values of i and j.

31. What is the syntax for a while loop in C?

ⓐ. while (condition) { }

ⓑ. while { }

ⓒ. (condition) { }

ⓓ. for (condition) { }

Explanation: The correct syntax for a while loop in C is "while (condition) { }".

32. In a while loop, what happens if the condition initially evaluates to false?

ⓐ. The loop executes indefinitely

ⓑ. The loop executes once

ⓒ. The loop does not execute at all

ⓓ. The loop executes until the condition becomes true

Explanation: If the condition in a while loop initially evaluates to false, the loop body will not execute at all.

33. What is the purpose of using the while loop over other loop constructs?

ⓐ. It offers better performance

ⓑ. It is simpler to implement

ⓒ. It can handle more complex conditions

ⓓ. It executes the loop body at least once

Explanation: The while loop executes the loop body at least once, making it suitable when you want to execute the loop body even if the condition is false initially.

34. What will be the output of the following code snippet?


int main() {
    int i = 5;
    while (i > 0) {
        printf("%d ", i);
        i--;
    }
    return 0;
}

ⓐ. 5 4 3 2 1

ⓑ. 1 2 3 4 5

ⓒ. 4 3 2 1

ⓓ. 5 4 3 2

Explanation: The loop iterates from i = 5 to i = 1 (inclusive), decrementing i by 1 in each iteration, and printing each value of i followed by a space.

35. Which of the following statements about the while loop is true?

ⓐ. The loop condition is evaluated after each iteration.

ⓑ. The loop condition is evaluated before each iteration.

ⓒ. The loop body must contain at least one statement.

ⓓ. The loop body can only contain one statement.

Explanation: In a while loop, the loop condition is evaluated before each iteration, and if it evaluates to true, the loop body is executed.

36. When should you use a while loop instead of a for loop?

ⓐ. When you need to execute the loop body a fixed number of times

ⓑ. When you need to execute the loop body at least once

ⓒ. When you need to handle nested loops

ⓓ. When you need to perform a specific number of iterations

Explanation: You should use a while loop instead of a for loop when you need to execute the loop body at least once, regardless of the initial condition.

37. What will be the output of the following code snippet?


int main() {
    int i = 0;
    while (i < 3) {
        printf("%d ", ++i);
    }
    return 0;
}

ⓐ. 1 2 3

ⓑ. 0 1 2

ⓒ. 1 2

ⓓ. 0 1 2 3

Explanation: The loop iterates from i = 0 to i = 2 (inclusive), incrementing i by 1 before printing its value.

38. Which statement about the loop control variable in a while loop is true?

ⓐ. It must always be declared inside the loop body.

ⓑ. It must always be declared before the loop.

ⓒ. It can be declared either inside or outside the loop.

ⓓ. It cannot be declared within a while loop.

Explanation: The loop control variable in a while loop can be declared either inside the loop initialization or outside the loop body, depending on the requirement.

39. What is the purpose of the continue statement in a while loop?

ⓐ. To terminate the loop prematurely

ⓑ. To skip the remaining code in the loop and proceed to the next iteration

ⓒ. To restart the loop from the beginning

ⓓ. To print a message and then continue to the next iteration

Explanation: The continue statement is used to skip the remaining code in the loop and proceed to the next iteration of the loop.

40. What will be the output of the following code snippet?


int main() {
    int i = 0;
    while (i < 3) {
        printf("%d ", i++);
        if (i == 2)
            break;
    }
    return 0;
}

ⓐ. 0 1

ⓑ. 0 1 2

ⓒ. 1 2

ⓓ. This code will result in an infinite loop

Explanation: The loop iterates from i = 0 to i = 1 (inclusive) due to the break statement when i becomes 2.

41. What is the main difference between a while loop and a do-while loop?

ⓐ. The syntax

ⓑ. The number of iterations

ⓒ. The loop condition evaluation

ⓓ. There is no difference

Explanation: In a while loop, the loop condition is evaluated before the loop body executes, while in a do-while loop, the loop body executes at least once before the condition is evaluated.

42. What will be the output of the following code snippet?


int main() {
    int i = 0;
    while (++i < 5) {
        printf("%d ", i);
    }
    return 0;
}

ⓐ. 1 2 3 4 5

ⓑ. 0 1 2 3 4

ⓒ. 1 2 3 4

ⓓ. 0 1 2 3

Explanation: The loop iterates from i = 1 to i = 4 (inclusive), printing each value of i followed by a space.

43. What is an infinite loop?

ⓐ. A loop that executes a fixed number of times

ⓑ. A loop that executes until a condition is true

ⓒ. A loop that executes indefinitely

ⓓ. A loop that executes only once

Explanation: An infinite loop is a loop that executes indefinitely unless terminated by an external factor like a break statement or a condition becoming false.

44. In a while loop, what does the expression "while(1)" represent?

ⓐ. A loop that never executes

ⓑ. A loop that executes once

ⓒ. An infinite loop

ⓓ. A loop that executes until the condition becomes false

Explanation: The expression "while(1)" represents an infinite loop because the condition is always true, causing the loop to execute indefinitely.

45. What will be the output of the following code snippet?


int main() {
    int i = 0;
    while (i < 5) {
        printf("%d ", ++i);
        if (i == 3)
            continue;
    }
    return 0;
}

ⓐ. 1 2 3 4 5

ⓑ. 1 2 3 4

ⓒ. 1 2 4 5

ⓓ. 1 2 3

Explanation: The loop iterates from i = 1 to i = 4 (inclusive), printing each value of i except when i is equal to 3 due to the continue statement.

46. What is the purpose of using the break statement in a while loop?

ⓐ. To skip the remaining code in the loop and proceed to the next iteration

ⓑ. To restart the loop from the beginning

ⓒ. To terminate the loop prematurely

ⓓ. To execute the loop body only once

Explanation: The break statement is used to terminate the loop prematurely, exiting the loop execution even if the loop condition is still true.

47. Which of the following statements about the loop condition in a while loop is false?

ⓐ. The loop condition must be a Boolean expression.

ⓑ. The loop condition is evaluated before each iteration.

ⓒ. The loop condition can be a numeric expression.

ⓓ. The loop condition can be evaluated using relational and logical operators.

Explanation: The loop condition in a while loop must be a Boolean expression, evaluating to either true or false.

48. What will be the output of the following code snippet?


int main() {
    int i = 5;
    while (i--) {
        printf("%d ", i);
    }
    return 0;
}

ⓐ. 4 3 2 1 0

ⓑ. 5 4 3 2 1

ⓒ. 5 4 3 2 1 0

ⓓ. 4 3 2 1

Explanation: The loop iterates from i = 5 to i = 1 (inclusive), decrementing i by 1 in each iteration, and printing each value of i except 0.

49. What happens if the loop condition in a while loop is initially false?

ⓐ. The loop executes indefinitely

ⓑ. The loop executes once

ⓒ. The loop does not execute at all

ⓓ. The loop executes until the condition becomes true

Explanation: If the loop condition in a while loop is initially false, the loop body will not execute at all.

50. In a while loop, what is the minimum number of times the loop body can execute?

ⓐ. 0

ⓑ. 1

ⓒ. 2

ⓓ. It depends on the loop condition

Explanation: In a while loop, if the loop condition is false initially, the loop body will not execute at all, resulting in the minimum number of executions being 0.

51. What is the syntax for a do-while loop in C?

ⓐ. do { } while ();

ⓑ. do { } until ();

ⓒ. while { } do ();

ⓓ. while () { }

Explanation: The correct syntax for a do-while loop in C is "do { } while ();".

52. In a do-while loop, when is the loop condition evaluated?

ⓐ. Before each iteration

ⓑ. After each iteration

ⓒ. Only at the beginning

ⓓ. It is never evaluated

Explanation: In a do-while loop, the loop condition is evaluated after each iteration, ensuring that the loop body is executed at least once.

53. Which of the following statements about the do-while loop is true?

ⓐ. The loop body must contain at least one statement.

ⓑ. The loop condition is optional.

ⓒ. The loop condition must be a Boolean expression.

ⓓ. The loop condition is evaluated before each iteration.

Explanation: In a do-while loop, the loop body must contain at least one statement.

54. What will be the output of the following code snippet?


int main() {
    int i = 0;
    do {
        printf("%d ", i);
        i++;
    } while (i < 3);
    return 0;
}

ⓐ. 0 1 2

ⓑ. 1 2 3

ⓒ. 0 1 2 3

ⓓ. 1 2

Explanation: The loop iterates from i = 0 to i = 2 (inclusive), printing each value of i followed by a space.

55. What is the purpose of using the do-while loop over other loop constructs?

ⓐ. It offers better performance

ⓑ. It is simpler to implement

ⓒ. It can handle more complex conditions

ⓓ. It executes the loop body at least once

Explanation: The do-while loop executes the loop body at least once, even if the loop condition is false initially.

56. What will be the output of the following code snippet?


int main() {
    int i = 5;
    do {
        printf("%d ", i);
        i--;
    } while (i > 0);
    return 0;
}

ⓐ. 5 4 3 2 1

ⓑ. 1 2 3 4 5

ⓒ. 5 4 3 2

ⓓ. 4 3 2 1

Explanation: The loop iterates from i = 5 to i = 1 (inclusive), printing each value of i followed by a space.

57. What will be the output of the following code snippet?


int main() {
    int i = 0;
    do {
        printf("%d ", ++i);
    } while (i < 3);
    return 0;
}

ⓐ. 1 2 3

ⓑ. 0 1 2 3

ⓒ. 1 2

ⓓ. 0 1 2

Explanation: The loop iterates from i = 1 to i = 3 (inclusive), printing each value of i followed by a space.

58. In a do-while loop, what is the primary advantage of having the loop condition evaluated after the loop body?

ⓐ. It allows for better optimization by the compiler.

ⓑ. It ensures that the loop body always executes at least once.

ⓒ. It simplifies the loop syntax.

ⓓ. It reduces the likelihood of infinite loops.

Explanation: Having the loop condition evaluated after the loop body ensures that the loop body always executes at least once, even if the loop condition is false initially.

59. Which of the following statements about the do-while loop is false?

ⓐ. It is suitable for situations where the loop body must execute at least once.

ⓑ. It is terminated by a break statement.

ⓒ. It evaluates the loop condition after each iteration.

ⓓ. It requires a semicolon (;) after the while keyword.

Explanation: The do-while loop is terminated by the loop condition becoming false, not by a break statement.

60. What will be the output of the following code snippet?


int main() {
    int i = 5;
    do {
        printf("%d ", i);
    } while (--i > 0);
    return 0;
}

ⓐ. 5 4 3 2 1

ⓑ. 1 2 3 4 5

ⓒ. 5 4 3 2

ⓓ. 4 3 2 1

Explanation: The loop iterates from i = 5 to i = 1 (inclusive), printing each value of i followed by a space.

61. What will be the output of the following code snippet?


int main() {
    int i = 10;
    do {
        printf("%d ", i);
    } while (i++ < 5);
    return 0;
}

ⓐ. 10

ⓑ. 10 11

ⓒ. 10 11 12

ⓓ. 10 11 12 13

Explanation: The loop iterates only once because the condition i++ < 5 evaluates to false initially since i is initially 10.

62. In a do-while loop, what happens if the loop condition evaluates to false initially?

ⓐ. The loop executes indefinitely

ⓑ. The loop executes once

ⓒ. The loop does not execute at all

ⓓ. The loop executes until the condition becomes true

Explanation: In a do-while loop, if the loop condition evaluates to false initially, the loop body executes once before the condition is evaluated.

63. What is the primary difference between a do-while loop and other loop constructs like while and for loops?

ⓐ. The loop syntax

ⓑ. The loop condition evaluation

ⓒ. The number of loop iterations

ⓓ. There is no difference

Explanation: The primary difference is that in a do-while loop, the loop condition is evaluated after each iteration, ensuring that the loop body executes at least once.

64. What will be the output of the following code snippet?


int main() {
    int i = 0;
    do {
        printf("%d ", i);
    } while (i-- > 0);
    return 0;
}

ⓐ. 0

ⓑ. 0 -1

ⓒ. 0 -1 -2

ⓓ. This code will result in an infinite loop

Explanation: The loop iterates only once because the condition i-- > 0 evaluates to false initially since i is initially 0.

65. What is the purpose of using the do-while loop over the while loop?

ⓐ. It offers better performance

ⓑ. It is simpler to implement

ⓒ. It can handle more complex conditions

ⓓ. It executes the loop body at least once

Explanation: The do-while loop executes the loop body at least once, even if the loop condition is false initially.

66. What will be the output of the following code snippet?


int main() {
    int i = 5;
    do {
        printf("%d ", i);
    } while (--i > 0);
    return 0;
}

ⓐ. 5 4 3 2 1

ⓑ. 1 2 3 4 5

ⓒ. 5 4 3 2

ⓓ. 4 3 2 1

Explanation: The loop iterates from i = 5 to i = 1 (inclusive), printing each value of i followed by a space.

67. What will be the output of the following code snippet?


int main() {
    int i = 1;
    do {
        printf("%d ", i++);
    } while (i <= 5);
    return 0;
}

ⓐ. 1 2 3 4 5

ⓑ. 2 3 4 5 6

ⓒ. 1 2 3 4

ⓓ. 1 2 3 4 5 6

Explanation: The loop iterates from i = 1 to i = 5 (inclusive), printing each value of i followed by a space.

68. In a do-while loop, what does the expression "do { } while(1)" represent?

ⓐ. A loop that never executes

ⓑ. A loop that executes once

ⓒ. An infinite loop

ⓓ. A loop that executes until the condition becomes true

Explanation: The expression "do { } while(1)" represents an infinite loop because the condition is always true, causing the loop to execute indefinitely.

69. Which of the following statements about the do-while loop is true?

ⓐ. It is terminated by the loop condition becoming true.

ⓑ. It requires a semicolon (;) after the while keyword.

ⓒ. It is suitable for situations where the loop body must execute at least once.

ⓓ. It evaluates the loop condition before each iteration.

Explanation: The do-while loop is suitable for situations where the loop body must execute at least once, even if the loop condition is false initially.

70. What will be the output of the following code snippet?


int main() {
    int i = 0;
    do {
        printf("%d ", ++i);
    } while (i < 3);
    return 0;
}

ⓐ. 1 2 3

ⓑ. 0 1 2 3

ⓒ. 1 2

ⓓ. 0 1 2

Explanation: The loop iterates from i = 1 to i = 3 (inclusive), printing each value of i followed by a space.

71. What is a nested loop?

ⓐ. A loop inside another loop

ⓑ. A loop with multiple conditions

ⓒ. A loop with multiple statements

ⓓ. A loop with multiple variables

Explanation: A nested loop is a loop that is placed inside another loop.

72. What is the primary purpose of using nested loops?

ⓐ. To execute multiple conditions simultaneously

ⓑ. To improve code readability

ⓒ. To handle multidimensional data structures

ⓓ. To reduce the number of iterations

Explanation: Nested loops are commonly used to iterate over multidimensional arrays or matrices.

73. What is the syntax for creating nested loops in C?

ⓐ. Nested loops are not supported in C

ⓑ. Using multiple for loops inside each other

ⓒ. Using multiple while loops inside each other

ⓓ. Using multiple do-while loops inside each other

Explanation: Nested loops in C are created by placing one or more loops inside the body of another loop, typically using for loops.

74. What will be the output of the following code snippet?


int main() {
    int i, j;
    for(i = 0; i < 3; i++) {
        for(j = 0; j < 2; j++) {
            printf("(%d, %d) ", i, j);
        }
    }
    return 0;
}

ⓐ. (0, 0) (0, 1) (1, 0) (1, 1) (2, 0) (2, 1)

ⓑ. (0, 0) (1, 0) (2, 0) (0, 1) (1, 1) (2, 1)

ⓒ. (0, 0) (0, 1) (1, 0) (2, 0) (1, 1) (2, 1)

ⓓ. (0, 0) (1, 0) (0, 1) (1, 1) (2, 0) (2, 1)

Explanation: This code snippet uses nested for loops to print combinations of values of i and j.

75. What is the maximum level of nesting allowed for loops in C?

ⓐ. 5

ⓑ. 10

ⓒ. 15

ⓓ. There is no specific limit

Explanation: There is no specific limit to the level of nesting allowed for loops in C, although excessively nested loops can lead to decreased code readability.

76. What will be the output of the following code snippet?


int main() {
    int i, j;
    for(i = 1; i <= 3; i++) {
        for(j = 1; j <= i; j++) {
            printf("%d ", j);
        }
        printf("\n");
    }
    return 0;
}

ⓐ. 1 1 2 1 2 3

ⓑ. 1 2 1 2 3

ⓒ. 1 2 3 1 2 3

ⓓ. 1 1 2 1 2 1 2 3

Explanation: This code snippet prints a pattern where each line contains numbers from 1 to the current row number.

77. What is the primary consideration when using nested loops?

ⓐ. Code efficiency

ⓑ. Code simplicity

ⓒ. Code performance

ⓓ. Code readability

Explanation: When using nested loops, code readability becomes crucial to ensure that the logic remains understandable and maintainable.

78. What will be the output of the following code snippet?


int main() {
    int i, j;
    for(i = 1; i <= 3; i++) {
        for(j = 3; j >= i; j--) {
            printf("%d ", j);
        }
        printf("\n");
    }
    return 0;
}

ⓐ. 3 2 1 2 1 1

ⓑ. 3 2 1 2 1

ⓒ. 3 2 1 2

ⓓ. 3 2 1

Explanation: This code snippet prints a pattern where each line contains numbers from the current row number to 1.

79. What is the term used to describe the process of iterating over each element of an array using nested loops?

ⓐ. Array traversal

ⓑ. Array manipulation

ⓓ. Array extraction

Explanation: Array traversal refers to the process of accessing and processing each element of an array, often accomplished using nested loops.

80. What is the primary challenge associated with nested loops?

ⓐ. Code optimization

ⓑ. Memory management

ⓓ. Increasing complexity

Explanation: As the level of nesting increases, code complexity also increases, which can make the code harder to understand and maintain.

81. What is the purpose of using nested loops in C programming?

ⓐ. To perform arithmetic operations

ⓑ. To create complex mathematical functions

ⓓ. To execute multiple conditional statements

Explanation: Nested loops are commonly used to traverse and manipulate multidimensional arrays or matrices.

82. What will be the output of the following code snippet?


int main() {
    int i, j;
    for(i = 1; i <= 3; i++) {
        for(j = 1; j <= i; j++) {
            printf("* ");
        }
        printf("\n");
    }
    return 0;
}

ⓐ. *
* *
* * *

ⓑ. * * *
* *
*

ⓓ. * * * *
* *
*

Explanation: This code snippet prints a triangular pattern of asterisks.

83. In a nested loop structure, what is an outer loop?

ⓐ. The loop with fewer iterations

ⓑ. The loop with the higher index variable

ⓓ. The loop that encloses another loop

Explanation: In nested loop structures, the outer loop encloses one or more inner loops.

84. What will be the output of the following code snippet?


int main() {
    int i, j;
    for(i = 1; i <= 4; i++) {
        for(j = 1; j <= i; j++) {
            printf("%d ", i * j);
        }
        printf("\n");
    }
    return 0;
}

ⓐ. 1
      2 4
      3 6 9
      4 8 12 16

ⓑ. 1
      2 3
      3 6 9
      4 8 12 16

ⓓ. 1
      2 4
      3 6 9
      4 8 12 16 20

Explanation: This code snippet prints a triangular pattern where each element is the product of its row and column numbers.

85. What is the term used to describe the process of combining two or more loops into a single loop?

ⓐ. Loop nesting

ⓑ. Loop merging

ⓒ. Loop fusion

ⓓ. Loop aggregation

Explanation: Loop fusion refers to the process of combining multiple loops into a single loop to improve code efficiency.

86. What will be the output of the following code snippet?


int main() {
    int i, j;
    for(i = 1; i <= 3; i++) {
        for(j = 3; j >= i; j--) {
            printf("%d ", j);
        }
        printf("\n");
    }
    return 0;
}

ⓐ. 3 2 1
3 2
3

ⓑ. 3 2 1
2 1
1

ⓒ. 3 3 3
2 2
1

ⓓ. 3 3 3
3 2
3

Explanation: This code snippet prints a triangular pattern of numbers decreasing from the maximum value.

87. Which of the following statements about nested loops is true?

ⓐ. The inner loop must always have a higher index variable than the outer loop.

ⓑ. Nested loops can only be created using for loops.

ⓓ. The number of iterations in nested loops can be calculated using the product of the iterations of each loop.

Explanation: The total number of iterations in nested loops is equal to the product of the iterations of each loop.

88. What will be the output of the following code snippet?


int main() {
    int i, j;
    for(i = 1; i <= 3; i++) {
        for(j = 1; j <= 4; j++) {
            printf("%d ", i + j);
        }
        printf("\n");
    }
    return 0;
}

ⓐ. 2 3 4 5
3 4 5 6
4 5 6 7

ⓑ. 1 2 3 4
2 3 4 5
3 4 5 6

ⓓ. 2 3 4 5
2 3 4 5
2 3 4 5

Explanation: This code snippet prints a rectangular pattern where each element is the sum of its row and column numbers.

89. What is the primary benefit of using nested loops?

ⓐ. Improved code performance

ⓑ. Reduced code complexity

ⓓ. Enhanced code scalability

Explanation: Nested loops allow for the handling of complex data structures and operations, enhancing the scalability of code.

90. What will be the output of the following code snippet?


int main() {
    int i, j;
    for(i = 1; i <= 3; i++) {
        for(j = 1; j <= i; j++) {
            printf("%d ", i * j);
        }
        printf("\n");
    }
    return 0;
}

ⓐ. 1
2 4
3 6 9

ⓑ. 1
2 3
3 4 5

ⓒ. 1
2 4
3 5 7

ⓓ. 1
2 3
3 6 9

Explanation: This code snippet prints a triangular pattern where each element is the product of its row and column numbers.

91. What is an infinite loop?

ⓐ. A loop that executes a fixed number of times

ⓑ. A loop that executes until a condition is true

ⓓ. A loop that executes only once

Explanation: An infinite loop is a loop that continues to execute indefinitely unless terminated by an external factor such as a break statement or a condition becoming false.

92. What is the primary cause of an infinite loop?

ⓐ. A syntax error

ⓑ. An unreachable condition

ⓓ. A missing loop counter

Explanation: An infinite loop often occurs due to a logical error where the loop condition is not properly updated or does not evaluate to false as expected.

93. Which of the following is a common method to create an infinite loop intentionally in C?

ⓐ. Using a loop counter with a large initial value

ⓑ. Using a loop counter with a small initial value

ⓓ. Using a loop counter initialized to a negative value

Explanation: Intentionally creating an infinite loop often involves setting up a loop counter with a large initial value that does not reach the loop termination condition.

94. What will be the output of the following code snippet?


int main() {
    int i = 0;
    while (i >= 0) {
        printf("%d ", i);
        i++;
    }
    return 0;
}

ⓐ. 0 1 2 3 ...

ⓑ. 0

ⓒ. No output

ⓓ. This code will result in an infinite loop

Explanation: This code will output consecutive non-negative integers starting from 0 and continuing indefinitely, resulting in an infinite loop.

95. What is a common strategy to terminate an unintentional infinite loop in C?

ⓐ. Restarting the computer

ⓑ. Terminating the program manually

ⓓ. Removing the loop counter initialization

Explanation: In many environments, pressing Ctrl+C on the keyboard sends an interrupt signal to terminate the program, including unintentional infinite loops.

96. What will be the output of the following code snippet?


int main() {
    while (1) {
        printf("Infinite loop\n");
        break;
    }
    printf("Loop terminated");
    return 0;
}

ⓐ. Infinite loop
Loop terminated

ⓑ. Infinite loop

ⓓ. No output

Explanation: The code enters an infinite loop but breaks out of it immediately, allowing the subsequent code to execute.

97. Which of the following statements is true regarding an infinite loop?

ⓐ. An infinite loop is always intentional.

ⓑ. An infinite loop is always unintentional.

ⓓ. An infinite loop cannot be terminated.

Explanation: Infinite loops can be intentional, for example, in programs designed to run continuously, or unintentional due to logical errors.

98. What will be the output of the following code snippet?


int main() {
    int i = 10;
    while (i < 20) {
        printf("%d ", i);
    }
    return 0;
}

ⓐ. No output

ⓑ. 10 11 12 13 ... (continues indefinitely)

ⓓ. This code will result in a compilation error

Explanation: The loop condition "i < 20" is never updated inside the loop, so it remains true indefinitely, resulting in an infinite loop.

99. What will be the output of the following code snippet?


int main() {
    int i = 5;
    while (i > 0) {
        printf("%d ", i--);
    }
    return 0;
}

ⓐ. 5 4 3 2 1

ⓑ. 1 2 3 4 5

ⓒ. 5 4 3 2

ⓓ. This code will result in an infinite loop

Explanation: The loop decrements i from 5 to 1 and prints each value.

100. What is a danger associated with unintentional infinite loops?

ⓐ. They consume excessive memory

ⓑ. They cause system crashes

ⓓ. They lead to slower program execution

Explanation: Unintentional infinite loops can consume system resources and may eventually lead to system crashes or freezes if not terminated.

101. What precaution should be taken to avoid unintentional infinite loops in C programming?

ⓐ. Avoid using while loops

ⓑ. Ensure that the loop counter is initialized with a large value

ⓓ. Use only nested loops

Explanation: To avoid unintentional infinite loops, it's crucial to ensure that the loop termination condition can be reached and is correctly updated within the loop body.

102. What is the term used to describe a condition that prevents an infinite loop from occurring?

ⓐ. Loop sentinel

ⓑ. Loop gate

ⓓ. Loop breaker

Explanation: A loop sentinel is a condition that, when met, terminates the loop and prevents it from running infinitely.

103. What will be the output of the following code snippet?


int main() {
    int i = 0;
    do {
        printf("%d ", i);
    } while (--i);
    return 0;
}

ⓐ. 0

ⓑ. No output

ⓓ. This code will result in a compilation error

Explanation: The loop condition "--i" decrements i before evaluating it, so when i becomes negative, the condition becomes false, leading to no output.

104. Which of the following statements about infinite loops is false?

ⓐ. An infinite loop consumes CPU resources indefinitely.

ⓑ. Infinite loops can be intentionally created.

ⓓ. Infinite loops always lead to system crashes.

Explanation: While infinite loops can consume CPU resources and cause programs to become unresponsive, they don't always lead to system crashes; however, they can if not properly handled.

105. What will be the output of the following code snippet?


int main() {
    int i = 0;
    while (i < 10) {
        printf("%d ", ++i);
        i = i - 2;
    }
    return 0;
}

ⓐ. 1 2 3 4 5 6 7 8 9 10

ⓑ. 1 3 5 7 9

ⓓ. This code will result in an infinite loop

Explanation: The loop increments i by 1 each iteration, then subtracts 2 from it, resulting in odd numbers less than 10 being printed.

106. What is the best practice for handling unintentional infinite loops during program development?

ⓐ. Ignoring them and relying on user feedback

ⓑ. Adding more conditions to the loop to prevent infinite execution

ⓓ. Letting the program run until it crashes and then fixing the issue

Explanation: Using debugging tools allows developers to identify the cause of unintentional infinite loops and fix the issue efficiently.

107. What will be the output of the following code snippet?


int main() {
    int i = 5;
    while (i > 0) {
        printf("%d ", i++);
    }
    return 0;
}

ⓐ. 5 6 7 8 9 ...

ⓑ. 5 6 7 8 9

ⓒ. No output

ⓓ. This code will result in an infinite loop

Explanation: The value of i is incremented inside the loop, causing it to continually increase without reaching the termination condition.

108. What can be used to break out of an infinite loop in C programming?

ⓐ. The continue statement

ⓑ. The exit function

ⓓ. The return statement

Explanation: The break statement is used to terminate the loop and exit it immediately, breaking out of an infinite loop.

109. What will be the output of the following code snippet?


int main() {
    int i = 0;
    while (1) {
        if (i > 5)
            break;
        printf("%d ", i);
        i++;
    }
    return 0;
}

ⓐ. 0 1 2 3 4 5

ⓑ. 0 1 2 3 4 5 6

ⓒ. No output

ⓓ. This code will result in an infinite loop

Explanation: The loop continues until i becomes greater than 5, at which point the break statement is encountered, terminating the loop.

110. What is the risk of using intentional infinite loops in C programming?

ⓐ. They may cause system instability.

ⓑ. They may lead to excessive CPU usage.

ⓓ. They may violate coding standards.

Explanation: Intentional infinite loops can lead to excessive CPU usage, especially in long-running programs, consuming system resources unnecessarily.

Looping Constructs (for loop, while loop, …etc) MCQ

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