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 stand of DNA containing 15 bases
const mockUpStrand = () => {
  const newStrand = []
  for (let i = 0; i < 15; i++) {
    newStrand.push(returnRandBase())
  }
  return newStrand
}
//factory function that creates objects that represent         P. aequor
const pAequorFactory = (specimenNum, dna) => {
  return {
    specimenNum,
    dna,
    mutate() { // function that simulates P. aequor‘s high rate of mutation
      randomBaseIndex = Math.floor(Math.random() * this.dna.length)
      let newBase = returnRandBase();
      while (this.dna[randomBaseIndex] === newBase) {
         newBase = returnRandBase();
      }
      this.dna[randomBaseIndex] = newBase;
      return this.dna;
    },
    compareDNA(newObj) { //compare the DNA sequences of different instances of simluated P. aequor, showing specimen number and percentage of DNA shared.
      let commonBases = 0;
      let mostRelated = [];
      let newStrand = newObj.dna;
      for (let i= 0; i < this.dna.length; i++) {
          if(this.dna[i] === newStrand[i]){
            commonBases++;
          }
        }
      let percentageShared = ( commonBases / this.dna.length) * 100;
      console.log(`Specimen #${this.specimenNum} and Specimen #${newObj.specimenNum} have ${percentageShared.toFixed()}% DNA in common.`)
    },
    willLikelySurvive() { // checks if the current specimen has a likely chance of survival based on how many C or G bases are in it's DNA strand.
      let survival = 0;
      for (const base of this.dna) {
        if (base === 'C' || base === 'G'){
          survival++;
        }
      }
      return survival / this.dna.length >= 0.6;
    },
    complementStrand() { // simulates the complementary strand of the current specimen's single DNA Strand.
      let complement = [];
      for (let i= 0; i < this.dna.length; i++){
        if (this.dna[i] === 'A') {
          complement.push('T');
        } else if (this.dna[i] === 'T') {
          complement.push('A');
        } else if (this.dna[i] === 'C') {
          complement.push('G');
        } else {
          complement.push('C')
        }
      }
      return complement;
    }
  }
}

// Sample of 30 simulated specimens with a likely chance of survival.
const surviveSpec = [];
let specCount = 1;

while (surviveSpec.length < 30) {
  let newSpec = pAequorFactory(specCount, mockUpStrand());
  if (newSpec.willLikelySurvive()) {
    surviveSpec.push(newSpec)
  }
  specCount++;
}


// testing section
const pAequor1 = pAequorFactory(1, mockUpStrand());
const pAequor2 = pAequorFactory(2, mockUpStrand());

console.log(pAequor1.dna)
console.log(pAequor1.complementStrand());