Solution to Practice Exercise

Practice Exercise: Sum of Two Numbers

This exercise demonstrates how data and methods work together in C to calculate the sum of two numbers.

Solution:

C

#include <stdio.h>

// Function to calculate the sum of two numbers

int calculateSum(int num1, int num2) {

  // Add the two numbers and store the result

  int sum = num1 + num2;

  // Return the calculated sum

  return sum;

}

int main() {

  // Declare variables to store two numbers

  int number1, number2;

  // Prompt the user to enter two numbers

  printf("Enter the first number: ");

  scanf("%d", &number1);

  printf("Enter the second number: ");

  scanf("%d", &number2);

  // Call the calculateSum function and store the result

  int totalSum = calculateSum(number1, number2);

  // Print the sum of the two numbers

  printf("The sum of %d and %d is %d\n", number1, number2, totalSum);

  return 0;

}

Use code with caution.

Explanation:

1. Header Inclusion: #include <stdio.h> includes the standard input/output library for functions like printf and scanf.

2. calculateSum Function:

   • Return Type: int indicates the function returns an integer value (the sum).

   • Parameters: int num1 and int num2 are the two numbers to be added.

   • Implementation:

     • int sum = num1 + num2; adds num1 and num2 and stores the result in sum.

     • return sum; returns the calculated sum to the calling function.

3. main Function:

   • Variable Declaration: int number1 and int number2 store the user-entered numbers.

   • User Input: printf prompts the user for input, and scanf reads the entered values into number1 and number2.

   • Function Call: int totalSum = calculateSum(number1, number2); calls the calculateSum function, passing number1 and number2 as arguments. The calculated sum is stored in totalSum.

   • Output: printf displays the original numbers and the calculated totalSum.

4. Return Statement: return 0; indicates successful program execution.

Compiling and Running:

1. Save the code as a .c file (e.g., sum.c).

2. Use a C compiler (e.g., GCC) to compile the code: gcc sum.c -o sum (This creates an executable named sum).

3. Run the program: ./sum

4. Enter two numbers when prompted. The program will display their sum.

This exercise showcases how data (user-entered numbers) is passed to a method (calculateSum), which performs the calculation (adding numbers) and returns the result (sum). The main function utilizes this result to display the final output.