Goldbach's Conjecture

goldbach.js

//calling goldbach(n) will give you two prime numbers that add up to it, as long as n is even. Otherwise it will just return [-1,-1]

function findPrimesLowerThan(n){
//find all primes less than or equal to the given n number
	primes = [2]
	current = 3

	while(current<n+1){
	isPrime = true
	for (i = 0; i<primes.length;i++){
		if (current % primes[i]==0){
			isPrime = false;
			}
	}
	if(isPrime){
	primes.push(current)

	}
	current++;
	}
	return primes;
}

//findPrimesLowerThan(5)

function goldbach(n){
//given a natural number n, find the two prime numbers that add up to it.
	if(n%2==1){
			return [-1,-1];	}
	primes= findPrimesLowerThan(n)
	for (i = 0 ; i<primes.length ; i++){
		for(j = 0 ; j<primes.length;j++){
			if (primes[i]+primes[j] == n){
				return [primes[i],primes[j]];
				}
				}
			}

	}
goldbach(28)