Codecademy export

main.js

// 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++) {
    newStrand.push(returnRandBase())
  }
  return newStrand
};

// Factory for Pila aequors
const pAqeuorFactory = (number,strand) => {
  return {
    specimenNum: number,
    dna: strand,
    mutate() {
      let randIndex = Math.floor(Math.random() * this.dna.length); // index to mutate
      let newBase = returnRandBase();
      while (this.dna[randIndex] == newBase) { // loop while newBase is equal to current base 
        newBase = returnRandBase(); // reroll newBase 
      };
      // console.log(`Current base: ${this.dna[randIndex]}`); 
      // console.log(`Mutated base: ${newBase}`); 
      // console.log(`Changed ${this.dna[randIndex]} to ${newBase} at index ${randIndex}`);
      this.dna[randIndex] = newBase; // mutate current base to new (after loop so newBase isn't equal to old base)
    },
    compareDNA(compareObject) {
      let counter = 0;
      for (let i = 0; i < this.dna.length; i++) {
        if (this.dna[i] === compareObject.dna[i]) { // checks identical bases at the same positions
          counter += 1;
        }    
      }
      console.log(`Specimen #${this.specimenNum} and specimen #${compareObject.specimenNum} have ${(counter/15 * 100).toFixed(2)}% DNA in common`);
    },
    willLikelySurvive() {
      const countCG = this.dna.filter(letter => letter === 'C' || letter === 'G'); // counter of 'C' and 'G' bases in dna
      if (countCG.length/this.dna.length > 0.6) { // if it's more than 60% of 'C' and 'G' bases
        return true;
      } else {
        return false;
      }
    }
  }
};

const sample = [];
let num = 1; // starting specimenNum
while (sample.length < 30) { // we need 30 samples
  let aqeuor = pAqeuorFactory(num,mockUpStrand());
  if (aqeuor.willLikelySurvive() === true) { // 30 samples of survivors
    sample.push(aqeuor);
    num += 1;
  }
};

//Tests only below
const pAqeuorOne = pAqeuorFactory(1,mockUpStrand()); 
const pAqeuorTwo = pAqeuorFactory(2,mockUpStrand());  

//Test for .mutate() method
console.log(`Starting DNA: ${pAqeuorOne.dna}`);
pAqeuorOne.mutate();
console.log(`Mutated DNA: ${pAqeuorOne.dna}`);

//Test for .compareDna() method
console.log(`DNA of specimen #${pAqeuorOne.specimenNum}: [${pAqeuorOne.dna}]`);
console.log(`DNA of specimen #${pAqeuorTwo.specimenNum}: [${pAqeuorTwo.dna}]`);
pAqeuorOne.compareDNA(pAqeuorTwo);

//Test for .willLikelySurvive() method
console.log(`P.aequor will survive: ${pAqeuorOne.willLikelySurvive()}`);