shen200001

// Returns a random DNA base
const returnRandBase = () => {
  const dnaBases = ['A', 'T', 'C', 'G'];
  return dnaBases[Math.floor(Math.random() * 4)]; 
};

// Returns a random single strand of DNA containing 15 bases
const mockUpStrand = () => {
  const newStrand = [];
  for (let i = 0; i < 15; i++) {

shen200001

// function to check if card number is valid using Luhns algorithm 

const validateCred = (arr) => {
  let algArr = [];
  
  //starting from right iterate to the left - every other digit is doubled. if doubled number is greater than 9, subtract 9
  
  for (let i = arr.length - 2; i >= 0; i -= 2) {
    if ((arr[i] * 2) > 9) {
    algArr.push((arr[i] * 2) - 9);