enhancedmath/lib/fibonacci.js

This package contains some enhanced mathematical operations

import { isNumber, isFraction } from './Helpers/index';
/**
 * Calculates the value of the row of Fibonnaci
 * @param {number} index The position of the number in the row of Fibonnaci
 * @returns {number} The value of the row of Fibonnaci
 */
const fibonacci = (index) => {
    if (index < 0 || !isNumber(index) || isFraction(index))
        return undefined;
    if (index < 2) {
        BigInt(1);
    }
    let temp = BigInt(0);
    let a = BigInt(1);
    let b = BigInt(0);
    while (index >= 0) {
        temp = a;
        a += b;
        b = temp;
        index--;
    }
    return b.valueOf();
};
export default fibonacci;