03/04/2021 - finding prime numbers

during a phone interview recently, i was how would i use javascript to find prime numbers below a a certain integer.

so far i have seldom touched javascript algorithms. only dabbled in python machine learning. but that is looking at other people's code.

i am feeling really insecure until i can solve the problem, even though the employer passed my feeble attempt.

here's the solution 

See the Pen prime number algo by wly185 (@wly185) on CodePen.

• use a for loop, other methods like map and filter seems to crash
• use for .. of to iterate through the array values 
• i added a break statement because i wanted to stop if the number was divisible and not search anymore, on to the next number
• filter out even numbers and number divisible by 5 (ends with 5 and zeros) to reduce the array length
• to generate an array, use array(integer) and fill(0) => an array with all zeros => map value to key index +1