CS Free MCQ Bank

[ 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 C ]

[ 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 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.

[ Option B ]

[ Option B ]

The loop starts with i = 2 and should print even numbers up to 10. To achieve this, we need to increase i by 2 in every iteration. Hence, using i+=2 ensures the loop prints 2 4 6 8 10.

[ Option C ]

[ Option B ]

An infinite loop can be exited using break, goto, or return, but not by using continue, since continue keeps the loop running.

• The goto can transfer control outside the loop unconditionally, so it can be used to exit an infinite loop.
• The break immediately terminates the loop and transfers control to the statement following the loop.
• The return exits the current function, and if the loop is inside that function, the loop also ends.

[ Option B ]

The loops are used to repeat a set of statements multiple times. In loops, the test condition can be checked either before or after executing the loop’s body. 
When the condition is checked before the loop body runs, it is called an entry-control loop. In this type of loop, the statements inside the loop will execute only if the condition is true. If the condition is false, the loop body will not run even once. The while and for loop are example of entry-control loop.
In an exit-control loop, the loop body runs first, and the condition is checked after execution. So, the loop runs at least once. The do-while loop is an example of exit-control loop.

[ Option B ]

In C language, some statements are designed to work only within loops. These statements control the execution of loop iterations.
The continue is used only inside loops. It skips the remaining statements of the current iteration and moves to the next iteration.

• The break can be used inside loops and switch-case statements, so it is not limited only to loops.
• The goto can be used anywhere in the program with a label. It is not limited to loops.
• The case is used only inside a switch statement, not inside loops.