Loop Control Statements : MCQs & PYQs with Explanation

Option D

The program is trying to reduce the numbers p and q by repeatedly subtracting the smaller one from the bigger one. This looks like the Euclidean method for finding the GCD, but there is a mistake in the loop condition. The loop only checks while(p != 0), so it keeps running as long as p is not zero.

When q becomes zero (which will always happen before p does), the subtraction stops changing the value of p because p = p - 0 will always give the same p. This means the program gets stuck, and the loop keeps running forever without ending.

So, instead of calculating the GCD, this program will go into an infinite loop. The correct way would be to stop when either p or q becomes zero, i.e., use while(p != 0 && q != 0).
 

Option D

The loop executes 3 times, incrementing both a and i in each iteration. After the loop ends, the value of a becomes 8. The statement printf("%d", a++); prints the current value of a, which is 8. Since it is a post-increment, a is increased to 9 after printing, but this updated value is not displayed.

Option C

Loops are used to repeat a block of code. The main difference between loops is when the condition is checked.

• Some loops check the condition before executing the loop body called entry-control loop. The while and for loops are kind of entry-control loop.
• Some loops check the condition after executing the loop body called exit-control loop. The do-while loop is kind of exit-control loop.

In exit-control loop the body is executed at least once, even if the condition is false at the beginning.

Option D

In C language, the break statement is a control statement used to immediately stop execution of certain program blocks. It is mainly used to come out of a loop or a switch statement when a specific condition is met.

Option B

Looping is a process in which a set of statements are executed repeatedly for a finite or infinite number of times, until a specific condition is met.
This repetition allows programs to automate tasks and efficiently handle large amounts of data or repeated actions.

Option A

Option C

The loop variable n is decremented twice in each iteration, once inside printf(n--) and once in the for loop (n--). When n reaches 1, it becomes 0 and then −1, so the condition n != 0 is always true afterward. Since n never becomes 0 again, the loop runs infinitely.

Option C

Option A

The program initializes sum to 0 and starts a for loop with i=1, where the condition i < 11 ensures that the loop runs from 1 to 10. During each iteration, the value of i is added to sum, gradually calculating the total sum of numbers from 1 to 10.
Iteration Process:

After the loop ends, sum = 55. So, printf(sum); prints 55.

Option B

In C, any non-zero value is treated as true in a loop condition. Here, i is initialized to 1024. The loop condition is simply i, so the loop runs as long as i is not zero.
In each iteration, i>>=1 performs a right shift, which divides i by 2. Thus, the values of i become 1024, 512, 256, 128, 64, 32, 16, 8, 4, 2, and 1. That makes 11 non-zero values, so "Suraku Academy" is printed 11 times. When i becomes 0, the loop terminates.

Option B

In C language, the post-decrement operator (n--) first uses the current value of the variable and then decreases it by 1. Also, in a while loop, the condition is checked before each iteration.
Initially, n = 0. In the condition (n--) != 0, the current value of n (0) is first compared with 0, which results in false, and then n is decremented to -1. Since the condition is false, the loop body is not executed even once. Finally, printf("%d",n); prints the updated value of n, which is -1.

Option A

The syntax of for loop is for(initialization; condition; increment). All three expressions are optional, but the semicolons are mandatory.
The for(;;); is valid. All expressions are empty, but semicolons are present. This creates an infinite loop with an empty body.

Option D

In C programming, the break statement is used to immediately exit a loop (for, while, or do-while), skipping the remaining statements in the loop body. When the break statement is encountered, control transfers to the statement immediately following the loop body.

• The continue statement instead skips the rest of the current iteration but continues with the next iteration of the loop.

for(int i = 1; i <= 8; i++) {
    if(i == 4) {
        break; // exits the loop when i equals 4
    }
    printf("%d ", i);
}
Output: 1 2 3

Option C

In C language, a semicolon (;) immediately after a loop makes it an empty loop, meaning the loop runs completely without executing any body.

• The semicolon (;) after for makes it an empty loop.
• Loop runs completely, and final value of i becomes 22. Hence, printf("%d", i); prints 22

Option B

When loops are nested, it means one loop is written inside another loop. The break statement is used to terminate the loop in which it appears. Remember, break affects only the nearest loop.
In nested loops, when a break statement is encountered inside the inner loop, it exits only the inner loop, and control returns to the outer loop.