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;
};

const pAequorFactory = (specimenNum, dna) => {
    return {
        specimenNum,
        dna,
        // changes a single random base
        mutate () {
          const index = Math.floor(Math.random() * this.dna.length);
          let oldBase = this.dna[index];
          let newBase = '';
          //ensures the base is different NOT WORKING
          do {
            newBase = returnRandBase();
          } 
          while (newBase === oldBase);
          this.dna[index] = newBase;
        },
        //Compares the similarity of the strands
        compareDNA (pAequor) {
          let numEqualPairs = 0;

          if (pAequor.dna.length !== this.dna.length) {
            console.log('DNA strands are different lengths');
          } else {
            for (let i = 0; i < this.dna.length; i++) {
              if(pAequor.dna[i] === this.dna[i]) {
                numEqualPairs++;
              }
            }
            const percentAlike = Math.round(numEqualPairs/this.dna.length*100);
            console.log(`Specimen #${this.specimenNum} and Specimen #${pAequor.specimenNum} have ${percentAlike}% DNA in common`);
          }
        },
        //tests if 60% or more of pairs are 'C' or 'G'
        willLikelySurvive () {
          let numCG = 0;
          //Counts C or G bases
          for (let i = 0; i < this.dna.length; i++) {
            if (this.dna[i] === 'C' || this.dna[i] === 'G') {
              numCG++;
            }
          }
          console.log(numCG +' '+ numCG/this.dna.length);
          if (numCG/this.dna.length >= 0.6) {
            return true;
          } else {
            return false;
          }
        }
    }
};


//Function creates N organisms likely to survive returns array of objects

function createCreatures(num) {
  let organisms = [];
  let numSurvived = 0;
  do {
    let sampCreature = pAequorFactory(numSurvived + 1, mockUpStrand());

    if(sampCreature.willLikelySurvive) {
      organisms.push(sampCreature);
      numSurvived++;
    }
  } while (numSurvived < num);
  return organisms;
}
  
creatures = createCreatures(30);
console.log(creatures);