Codecademy export

main.js

// Returns a random DNA base from the array
const returnRandomBase = () => {
  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(returnRandomBase());
  }
  return newStrand;
};

const mutateFn = (arr) => {
  elToMutate = arr[Math.floor(Math.random() * 15)];
  const index = arr.indexOf(elToMutate);
  if (elToMutate === "A") {
    arr[index] = ["C", "G", "T"][Math.floor(Math.random() * 3)];
  }
  if (elToMutate === "C") {
    arr[index] = ["A", "G", "T"][Math.floor(Math.random() * 3)];
  }
  if (elToMutate === "G") {
    arr[index] = ["C", "A", "T"][Math.floor(Math.random() * 3)];
  }
  if (elToMutate === "T") {
    arr[index] = ["C", "G", "A"][Math.floor(Math.random() * 3)];
  }
  return arr;
};

const pAequorFactory = (num, arr) => {
  const obj = {
    specimenNum: num,
    dna: arr,
    mutate() {
      mutateFn(arr);
    },
    compareDNA(object) {
      let comp1 = this.dna;
      let comp2 = object.dna;
      let totalNum = 0;
      for (i = 0; i < comp1.length; i++) {
        for (j = 0; j < comp2.length; j++) {
          if (comp1[i] === comp2[j]) {
            totalNum++;
          }
        }
      }
      const percentage = (totalNum / comp1.length).toFixed(2) + "%";
    },
    returnComparedDNA(object) {
      let similar = 0;
      object.dna.forEach((base, idx) => {
        if (base === object.dna[idx]) {
          similar++;
        }
      });
      return similar;
    },
    willLikelySurvive() {
      let cgTotal = 0;
      for (i = 0; i < this.dna.length; i++) {
        if (this.dna[i] === "C" || this.dna[i] === "G") {
          cgTotal++;
        }
      }
      const cgPercentage = 0.6 * this.dna.length;
      return cgTotal >= cgPercentage ? true : false;
    },
    complementStrand() {
      let complementaryStrand = [];
      for (let i = 0; i < this.dna.length; i++) {
        if (this.dna[i] === "A") {
          complementaryStrand.push("T");
        } else if (this.dna[i] === "T") {
          complementaryStrand.push("A");
        } else if (this.dna[i] === "C") {
          complementaryStrand.push("G");
        } else if (this.dna[i] === "G") {
          complementaryStrand.push("C");
        } else complementaryStrand.push(this.dna[i]);
      }
      return complementaryStrand;
    },
  };
  return obj;
};

const createPool = () => {
  const survivingSpecimen = [];
  let i = 1;
  while (survivingSpecimen.length < 30) {
    let sample = pAequorFactory(i, mockUpStrand());
    if (
      sample.willLikelySurvive() &&
      survivingSpecimen.indexOf(sample) === -1
    ) {
      survivingSpecimen.push(sample);
      i++;
    }
  }
  return survivingSpecimen;
};

const mostRelatedSpecimen = () => {
  const survivingSpecimen = createPool();
  let instance1;
  let instance2;
  let similarity = 0;
  survivingSpecimen.forEach((el) => {
    survivingSpecimen.forEach((el2) => {
      if (
        el2.returnComparedDNA(el) > similarity &&
        el.specimenNum !== el2.specimenNum
      ) {
        similarity = el2.returnComparedDNA(el);
        instance1 = el.specimenNum;
        instance2 = el2.specimenNum;
      }
    });
  });
  console.log(
    `Two most related specimen of P. aequor are ${instance1} and ${instance2} with ${similarity}% DNA in common.`
  );
};