Find the prime factors of a number in JavaScript
The prime factors of a number are the prime numbers that divide the number exactly. An easy way to find the prime factors of a number is using trial division, which is a simple algorithm that checks each possible prime factor in order.
This algorithm is not efficient for large numbers, as it has a high time complexity. You should look into more efficient algorithms for prime factorization, if you plan to implement this in a production environment.
Implementing the algorithm is straightforward. You can use a while loop to iterate over all possible prime factors, starting with 2. If the current factor, f, exactly divides n, add f to the factors array and divide n by f. Otherwise, increment f by one.
const primeFactors = n => { let a = [], f = 2; while (n > 1) { if (n % f === 0) { a.push(f); n /= f; } else { f++; } } return a; }; primeFactors(147); // [3, 7, 7]
