C Program: Print first 10 Fibonacci numbers - While loop

Last update on March 18 2025 13:38:53 (UTC/GMT +8 hours)

10. Fibonacci Sequence Generation Using a While Loop

Write a C program to find and print the first 10 Fibonacci numbers using a while loop.

Sample Solution:

C Code:

#include <stdio.h>

int main() {
    int count = 10;          // Number of Fibonacci numbers to generate
    int firstTerm = 0, secondTerm = 1;  // Initialize the first two terms of the sequence

    printf("First %d Fibonacci numbers:\n", count);

    // Start a while loop to generate Fibonacci numbers
    while (count > 0) {
        printf("%d, ", firstTerm);  // Print the current Fibonacci number
        int nextTerm = firstTerm + secondTerm;  // Calculate the next Fibonacci number
        firstTerm = secondTerm;  // Update the first term with the value of the second term
        secondTerm = nextTerm;   // Update the second term with the calculated next term
        count--;  // Decrease the count for the next iteration
    }

    return 0;  // Indicate successful program execution
}

Sample Output:

First 10 Fibonacci numbers:
0, 1, 1, 2, 3, 5, 8, 13, 21, 34,

Explanation:

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

Variable initialization:

count: Number of Fibonacci numbers to generate (set to 10).
firstTerm and secondTerm: Initialize the first two terms of the Fibonacci sequence.

Print Statement:

Prints a message indicating the intent to display the first 10 Fibonacci numbers.

While Loop (Fibonacci Generation):

Enters a while loop that continues until 'count' becomes 0.
Prints the current Fibonacci number ('firstTerm').
Calculates the next Fibonacci number ('nextTerm') by adding the first and second terms.
Updates the first and second terms for the next iteration.
Decreases the count for the next iteration.

Return Statement:

Indicates successful program execution.

Flowchart:

For more Practice: Solve these Related Problems:

Write a C program to print the first 10 Fibonacci numbers using a while loop and then calculate their sum.
Write a C program to generate the first 10 Fibonacci numbers using a while loop and display them in reverse order.
Write a C program to print the first 10 Fibonacci numbers using a while loop and then output the ratio of consecutive Fibonacci numbers.
Write a C program to generate the first 10 Fibonacci numbers using a while loop and check which of them are prime numbers.

C Programming Code Editor:

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