Variable Practice

Here are some exercises that will help you get a better grasp of using variables! (Try solving these by hand without a compiler!)

1. Write one line of code that declares an integer called cups_of_tea and assigns to it a value of 5.

2. What is wrong with the following code? How can you fix it?

#include <stdio.h>

int main(void)
{
  printf("The value of x is %d.\n", x);

  int x = 7;

  return 0;
}

3. Which of the following are not valid variable names? If any are invalid, explain why.

• __basic
• apple#3
• 2023_year
• INT
• orANGE
• total students
• 982
• float_

4. Which of the following statements are not valid in C? If any are invalid, explain why.

• int float = 34123.4123 * 4;
• char student_name = 'John Smith';
• int i = 0; i = i + 1;
• 4 = gpa;

5. What is wrong with the following code? How can you fix it?

#include <stdio.h>

int main(void)
{
  ounces_of_milk = 16.0;
  printf("You have %lf ounces of milk.\n", ounces_of_milk);

  return 0;
}

6. What is the final output of this program?

#include <stdio.h>

int main(void)
{
  int apples = 16;
  int oranges = 90;

  apples = oranges;
  oranges = apples;

  printf("You have %d apples and %d oranges.\n", apples, oranges);

  return 0;
}