Challenge Project: Mysterious Organism

mystery-organism.js

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 Function
const pAequorFactory = (num, arr) => {
  const organism = {
    specimenNum: num,
    dna: arr,
    mutate() {
      const randomBase = this.dna[Math.floor(Math.random() * this.dna.length)];
      const newBase = this.dna.filter((arr) => {
        if (arr[Math.floor(Math.random() * this.dna.length)] === "A") {
          let notA = ["T", "C", "G"];
          return (arr[randomBase] = notA[Math.floor(Math.random() * notA.length)]);
        } else if (arr[Math.floor(Math.random() * this.dna.length)] === "T") {
          let notT = ["A", "C", "G"];
          return (arr[randomBase] = notT[Math.floor(Math.random() * notT.length)]);
        } else if (arr[Math.floor(Math.random() * this.dna.length)] === "C") {
          let notC = ["A", "T", "G"];
          return (arr[randomBase] = notC[Math.floor(Math.random() * notC.length)]);
        } else if (arr[Math.floor(Math.random() * this.dna.length)] === "G") {
          let notG = ["A", "T", "C"];
          return (arr[randomBase] = notG[Math.floor(Math.random() * notG.length)]);
        } else {
          return "ERROR";
        }
      });
      return newBase;
    },
    compareDNA (paObj) {
      const identicalBases = this.dna.filter((val, i) => paObj[i] === val );
      const identicalBasesPercentage = identicalBases.length/this.dna.length * 100
      return `specimen #1 and specimen #2 have ${identicalBasesPercentage.toFixed()}% DNA in common.`
    },
    willLikelySurvive() {
      let cdCount = 0;    
        this.dna.forEach(element => {
          if (element === 'C' || element === 'G') {
            cdCount += 1;
          }
        });
      const cdBases = cdCount/this.dna.length * 100;
          if(cdBases > 60){
            return true
          } else {
            return false
          }
    }
  };
  return organism;
};

const paSurvivors = []
let idCounter = 1

while(paSurvivors.length < 30){
  let newOrg = pAequorFactory(idCounter, mockUpStrand());
    if (newOrg.willLikelySurvive()) {
      paSurvivors.push(newOrg);
    }
    idCounter++;
}

console.log(paSurvivors);