do while , for, Arrays

Which loop type will always execute at least once, regardless of the condition?

• do-while loop

• while loop

• for loop

• foreach loop

If a for loop has a condition i < 10, but inside the loop, we have a statement i += 3;, how many times will it run starting from i = 0?

• 6

• 4

• 3

• 5

Answer explanation

Starting from i = 0, the loop increments i by 3 each time: 0, 3, 6, 9. After that, i becomes 12, which is not less than 10. Thus, the loop runs 4 times before exiting.

Which of the following correctly initializes a 2D array in C++ with all zeros?

• • int arr[3][3] = {};

• • int arr[3][3] = {0};

• • int arr[3][3] = { {0, 0, 0}, {0, 0, 0}, {0, 0, 0} };

• • All of the above

Which loop is most appropriate for iterating over elements when the number of iterations is known in advance?

• do-while loop

• while loop

• for loop

• foreach loop

Which statement about arrays in C++ is true?

• • Array indices start at 1.

• Arrays in C++ can store elements of different types.

• Arrays in C++ store elements of the same type.

• • Array size must be specified at the time of declaration.

In a 2D array declared as int matrix[3][3];, how do you access the element at the first row and second column?

• matrix[0][1]

• matrix[0][2]

• matrix[2][1]

• matrix[1][0]

What will be the output of the following code?

• • 100

• 20

• 90

• 40

Answer explanation

The loop accesses elements at indices 1 and 3 (arr[1] = 20, arr[3] = 40), so sum = 20 + 40 = 60.

Write a program that initializes a 1D array of size 5, prompts the user to input values, and prints the array in reverse order.

Consider the code below. How many times will the do-while loop run?

• 0

• 1

• 5

• Infinite

What will the output be for the following code snippet?

• 2

• 3

• 6

• 10