Exploring Fibonacci Series in Ballerina: Iterative vs. Recursive Approaches

Fibonacci Series Using Ballerina:

The Fibonacci series is an easy concept in programming, often used to show how recursion works. Each number in the series is the sum of the two numbers before it, starting with 0 and 1. In this blog, we’ll explore how to generate the Fibonacci series using the Ballerina programming language, both iteratively and recursively.

What is Fibonacci Series?:

The Fibonacci series starts with 0 and 1, and each following number is the sum of the previous two numbers. Here’s how the series looks for the first few terms:

0, 1, 1, 2, 3, 5, 8, 13, 21, 34...

In mathematical terms, the Fibonacci sequence can be defined as:

• Fib(0) = 0

• Fib(1) = 1 *Fib(n) = Fib(n - 1) + Fib(n - 2) for n > 1

Steps of Fibonacci Series in Iterative Approach:

1. Start with an array containing the first two terms 0 and 1.

2. Use a foreach loop to calculate each following term in the series.

3. For each new term, add the last two numbers in the array to get the next number in the series and append this new term to the array.

4. Once the loop has generated the desired number of terms, return the entire array containing the complete Fibonacci sequence up to the specified term.

Steps of Fibonacci Series in Recursive Approach:

1. generateFibonacci function creates the whole Fibonacci series by calling fibonacciRecursive to get each term in the series

2. Start a loop with i beginning at 0 and continuing up to n - 1, where n is the number of terms we want in the Fibonacci series.

3. For each value of i, call the fibonacciRecursive(i) function to calculate the i-th Fibonacci number.

4. Take the result of fibonacciRecursive(i) and add (push) it to the fibSeries array.

5. The fibonacciRecursive function follows the Fibonacci rule by calling itself with n - 1 and n - 2 until it reaches the base cases of 0 or 1.

6. Calculate the current term using fibonacciRecursive(n -1) + fibonacciRecursive(n - 2).

7. Base case reaches if n <= 1.

8. In the base case simply return n.

Implementation of Fibonacci Series in Ballerina:

1. Start by creating a new Ballerina project.

2. Open a terminal and enter the following command: bal new fibonacci_example.

3. Open the main.bal file and write the Fibonacci Series code.

4. Save the code and run the program using this command in the terminal: bal run.

Code Snippet in Iterative Approach:

Following is the coding implementation of the Fibonacci series in an iterative approach:

import ballerina/io;

// Iterative function to generate Fibonacci series
function fibonacciIterative(int n) returns int[] {
    int[] fibSeries = [0, 1];

    // Generate the series until it reaches 'n' terms
    foreach int i in 2 ... n - 1 {
        int nextTerm = fibSeries[i - 1] + fibSeries[i - 2];
        fibSeries.push(nextTerm);
    }

    return fibSeries;
}

public function main() {
    int n = 10;
    io:println("Fibonacci Series in Iterative approach: ", fibonacciIterative(n));
}

Code Snippet in Recursive Approach:

Following is the coding implementation of the Fibonacci series in a recursive approach:

import ballerina/io;

// Recursive function to get the term
function fibonacciRecursive(int n) returns int {
    if n <= 1 {
        return n;
    }
    return fibonacciRecursive(n - 1) + fibonacciRecursive(n - 2);
}

// Recursive function to generate Fibonacci terms up to n
function generateFibonacci(int n) returns int[] {
    int[] fibSeries = [];

    foreach int i in 0 ... n - 1 {
        fibSeries.push(fibonacciRecursive(i));
    }

    return fibSeries;
}

public function main() {
    int n = 10;
    io:println("Fibonacci Series in recursive approach: ", generateFibonacci(n));
}