Lab 8- Exam 2 Review

What will be displayed to the screen?

#include <stdio.h>

int main()

{

int num1 =20, num2= 2, num3=3;

int small =num1;

if (small>num2)

{

small =num2;

}

if (small>num3)

{

small=num3;

}

printf("%d", small);

return 0;

}

• 20

• 2

• 3

• I don't know

Answer explanation

The code will display 2 onto the screen. The first line of the program is setting a temporary variable called "small" to be the same value as num1. We then compare small to num2. If num2 is less than small, we set small to num2. The program will then go to the second if statement. If num3 is less than small, set small to num3.

What are the three different kinds of loops?

• For loop, while loop, if loop

• For loop, while do loop, while loop

• For loop, do while loop, while loop

Which loop is the best to use for the following prompt:

Create a program where a user enters multiple numbers. The program should add up all of the numbers until the user enters 0. Example output:

Enter a number: 1.5

Enter a number: 2.4

Enter a number: -3.4

Enter a number: 4.2

Enter a number: 0

Sum = 4.70

• do while loop

• while loop

• for loop

• if loop

Answer explanation

We use a while or a do while loop when we want the program to run as long as a specific condition is met. A do while loop will run one time before the condition is tested. Either loop could be used. However, it is best to use a do while loop because we want the code to run at least one time before we test the condition.

We do not use a for loop in this case because we do not know how many numbers the user wants to enter. Therefore, we do not know how many times the loop needs to run.

Which loop would be best to use for the following prompt?

Create a program that displays the temperature as long as it is sunny outside.

• do while

• while

• for

Answer explanation

A while loop would be better for this prompt because we want the temperature to be displayed only when the weather outside is sunny. We could use a do while loop for this example. However, the do while loop would display the temperature before testing if the condition is met.

We would not use a for loop because we do not know how many times the user will enter a value in.

Which loop would be best for the following prompt?

Create a program that asks the user to enter multiple numbers and add these numbers together. The user should enter how many values they want to enter. Example output:

How many numbers would you like to enter: 3

Enter number: 23

Enter number: 2

Enter number 5

Sum is 30

• do while

• while

• for

Answer explanation

We will use a for loop since we know how many times the loop needs to run.

You would not use a while or a do while loop because there is not a specific condition that needs to be met.

Write a function prototype for the following prompt:

Create a function that takes in two integers and one character. The function will return a double. The function will add the two integers.

• int function (double num1, int num2, num3, char letter);

• double function (int num1, int num2, char letter);

• char function (double num1, num2, int num3)

  {

  double sum=num1+num2;

  return 'c';

  }

• double ans=function(2, 4, 'c');

Answer explanation

The function prototype goes at the top of your code. It goes under the #include <stdio.h> and above the main function. The function prototype looks like the following:

returnType function_name (variable).

How do you declare a pointer?

• int numptr

• point int numptr

• int * numptr

How do you get a pointer to point to a variable?

• int *numptr;

  numptr=c;

• int *numptr;

  numptr=&c

• int numptr;

  numptr=c

• int numptr;

  numptr=&c

Answer explanation

The & sign means the address of the variable. Therefore, we are saying that the pointer is pointing to the address of variable C.

How do you print out the value of the contents of the memory cell that the pointer is pointing to?

• printf("%d", *numptr);

• printf("%d", numptr);

• printf("%d", &numptr);

• printf("%p", numptr);

Answer explanation

To access the value that the pointer is pointing to, we need to use a *.

What will be printed to the screen?

int* pc;

int c;

c = 5;

pc = &c;

printf("%d", *pc);

• 5

• 234564 (address of the variable, c)

• Error

• I don't know

Answer explanation

When we want to access the contents of the variable that the pointer is pointing to, we use an *. Therefore, we will be printing 5 to the screen.