C Program: Calculate average of user input numbers

C Do-While Loop: Exercise-7 with Solution

Write a C program that calculates the average of a set of numbers input by the user. The user should be able to input as many numbers as desired, and the program should continue until the user decides to stop.

Sample Solution:

C Code:

#include <stdio.h>

int main() {
    int count = 0;  // Variable to store the number of entered values
    double sum = 0.0;  // Variable to store the sum of entered values
    double number;  // Variable to store the user input

    // Prompt the user to enter numbers and calculate the average
    printf("Input numbers to calculate the average (enter a non-numeric value to stop):\n");

    while (1) {
        // Read the user input
        printf("Input a number: ");
        if (scanf("%lf", &number) != 1) {
            // If the input is not a valid number, break out of the loop
            break;
        }

        // Add the entered number to the sum
        sum += number;
        // Increment the count of entered values
        count++;
    }

    // Check if any numbers were entered
    if (count > 0) {
        // Calculate and print the average
        double average = sum / count;
        printf("Average of input numbers: %.2lf\n", average);
    } else {
        // If no numbers were entered, print a message
        printf("No numbers were entered.\n");
    }

    return 0; // Indicate successful program execution
}

Sample Output:

Input numbers to calculate the average (enter a non-numeric value to stop):
Input a number: 3
Input a number: 1
Input a number: 12
Input a number: -12
Input a number: 6
Input a number: a
Average of input numbers: 2.00

Explanation:

Here are key parts of the above code step by step:

• int count = 0;: Initializes a variable to store the number of entered values.
• double sum = 0.0;: Initializes a variable to store the sum of entered values.
• double number;: Declares a variable to store user input.
• while (1) { ... }: Creates an infinite loop.
• printf("Enter numbers to calculate the average (enter a non-numeric value to stop):\n");: Displays a message to the user.
• if (scanf("%lf", &number) != 1) { ... }: Reads user input and checks if it's a valid number. If not, breaks out of the loop.
• sum += number;: Adds the entered number to the sum.
• count++;: Increments the count of entered values.
• if (count > 0) { ... }: Checks if any numbers were entered.
• double average = sum / count;: Calculates the average.
• printf("Average of entered numbers: %.2lf\n", average);: Prints the calculated average.
• else { printf("No numbers were entered.\n"); }: If no numbers were entered, prints a message.
• return 0;: Indicates successful program execution.

Flowchart:

C Programming Code Editor:

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