mysterious-organism.js

/**
 * Codecademy mini challenge: Mysterious organism
 * https://www.codecademy.com/paths/front-end-engineer-career-path/tracks/fecp-javascript-syntax-part-ii/modules/fecp-challenge-project-mysterious-organism/projects/mysterious-organism
 */


/** Provided helpers */
// Returns a random DNA base
const returnRandBase = (_dnaBases = []) => {
  if (!_dnaBases.length)
    _dnaBases = ['A', 'T', 'C', 'G']

  return _dnaBases[indexRandomizer(_dnaBases.length)];
};

// 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;
};

/** Challenge implementation  */

const log = console.log
const clear = console.clear

// To generate a random number with a given length
const indexRandomizer = len => Math.floor(Math.random() * len)

/**
 * P.Aequor factory method
 * 
 * @param {number} specimenNum 
 * @param {array} dna - generated by mockupStrand()
 * @returns object
 */
function PaequorFactory(specimenNum, dna) {
  const pAequor = {
    specimenNum,
    dna,
    mutate() {
      // Pick a randomly selected target base => get its index
      const targetIndex = indexRandomizer(this.dna.length)

      // New selected bases must be different from the last base
      // e.g: `A` is replaced by `T`, `G`, or `C` but NOT `A`
      const possibleBases = this.dna.filter(db => db !== this.dna[targetIndex])

      // Assign the randomly selected to the given target base
      this.dna[targetIndex] = possibleBases[indexRandomizer(possibleBases.length)]
    },
    compareDNA(targetPaequor) {
      // compute num of identical bases (in the same locations)
      const sameness = this.dna.reduce((acc, cur, idx, arr) => {
        if (arr[idx] === targetPaequor.dna[idx])
          return acc + 1
        else
          return acc
      }, 0)

      // converted to percentage
      const percentage = (sameness / this.dna.length * 100).toFixed(2)

      // Output
      log(`specimen #${this.specimenNum} and specimen #${targetPaequor.specimenNum} have ${percentage}% DNA in common.`)
    },
    willLikelySurvive() {
      const surviveCount = this.dna.filter(dna => ['C', 'G'].includes(dna))

      return (surviveCount.length / this.dna.length) * 100 >= 60
    },
    report() {
      log(`---< Report specimen #${this.specimenNum} >---`)
      console.table({
        id: this.specimenNum,
        dna: this.dna.join(' '),
        survival: this.willLikelySurvive()
      })
    }
  };

  return pAequor
}

const testables = []
let counter = 0

while (testables.length < 10) {
  testables.push(PaequorFactory(counter + 1, mockUpStrand()))
  // testables[counter].report()
  counter += 1
}
testables[2].report()
testables[5].report()
testables[2].compareDNA(testables[5])