#!/bin/env node function do_fibo (num_f) { let a, b, c; a = num_f('0'); b = num_f('1'); for (let i = 0; i < 101; i += 1) { c = a + b; console.info(c.toString()); b = a; a = c; } } function parse_flag (s) { s = s.toLowerCase(); if (s === 'true') { return true; } else if (s === 'false') { return false; } return Number(s); } const flag = process.argv.length > 2 ? parse_flag(process.argv[2]) : true; if (flag) { do_fibo(BigInt); } else { do_fibo(Number); }