Codecademy - Open Exercise (pAequor DNA Research)

// 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
}

// Create a factory function for pAequor
function pAequorFactory(num, DNABasesArray){
  return {
    specimenNum: num,
    dna: DNABasesArray,
    mutate(){
      let randomIndex = Math.floor(Math.random() * 15);
      let base = this.dna[randomIndex];
      let newBase = returnRandBase();
      while(base === newBase){
        newBase = returnRandBase();
      }
      // I will copy the dna array to new array
      let newDNA = this.dna.slice();
      newDNA[randomIndex] = newBase;
      return newDNA;
    },
    compareDNA(otherPAequor){
      let sum = 0;
      for(let i=0; i<15; i++){
        if(this.dna[i] === otherPAequor.dna[i]){
          sum += 1;
        }
      }
      console.log(`We compared the 2 DNA chains of pAequors with ids: ${this.specimenNum} and ${otherPAequor.specimenNum}.`);
      let percentage = (Math.round(10000 * sum / 15)) / 10000;
      console.log("We found out that these 2 pAequors samples are similar in the percentage of " + (100 * percentage) + "%.");
    },
    willLikelySurvive(){
      let sum = 0;
      for(let i=0; i<15; i++){
        if(this.dna[i] === 'C' || this.dna[i] === 'G'){
          sum += 1;
        }
      }
      if(sum / 15 >= 0.6){
        return true;
      }
      else{
        return false;
      }
    },
    complementaryStrand(){
      let complement = [];
      for(let i=0; i<15; i++){
        if(this.dna[i] === 'A'){
          complement.push('T');
        }
        else if(this.dna[i] === 'T'){
          complement.push('A');
        }
        else if(this.dna[i] === 'G'){
          complement.push('C');
        }
        else if(this.dna[i] === 'C'){
          complement.push('G');
        }
      }
      return complement;
    }
  };  // END OF RETURNED OBJECT
}  // END OF FACTORY FUNCTION

let dnaBases = mockUpStrand();
let pAequor = pAequorFactory(1, dnaBases);
let dnaBases2 = mockUpStrand();
let pAequor2 = pAequorFactory(2, dnaBases2);
console.log("pAequors:");
console.log(pAequor);
console.log(pAequor2);
console.log();
console.log("DNA chains of the 2 pAequors and the 2 mutations of them:");
console.log(dnaBases);
console.log(pAequor.mutate());
console.log();
console.log(dnaBases2);
console.log(pAequor2.mutate());
console.log();
console.log("Compare the 2 DNAs:");
pAequor.compareDNA(pAequor2);
console.log();
console.log("pAequor will likely survive? " + pAequor.willLikelySurvive());
console.log("pAequor2 will likely survive? " + pAequor2.willLikelySurvive());

// Now, I want to create 30 instances of pAequor object (using the pAequorFactory() function), that can survive in their natural environment
pAequorArray = [];
let counter = 0;
while(pAequorArray.length < 30){
  counter++;
  let pAequorInstance = pAequorFactory(counter, mockUpStrand());
  if(pAequorInstance.willLikelySurvive() === true){
    pAequorArray.push(pAequorInstance);
  }
}
//console.log();
//console.log(pAequorArray);

// Now, the variable 'pAequorArray' includes the 30 specimens that survived
console.log();
console.log("Complementary DNA chains: ");
console.log(pAequor.complementaryStrand());
console.log(pAequor2.complementaryStrand());

// Last task is to scan the array of pAequor instances and find the 2 most related instances
let maxPercentage = 0;
let maxI = 0;
let maxJ = 0;
for(let i=0; i<pAequorArray.length; i++){
  let instance1 = pAequorArray[i];
  for(let j=0; j<pAequorArray.length; j++){
    let instance2 = pAequorArray[j];
    if(i != j){  // In order to compare the different instances
      let sum = 0;
      for(let k=0; k<instance1.dna.length; k++){
        if(instance1.dna[k] === instance2.dna[k]){
          sum += 1;
        }
      }
      let percentage = sum / instance1.dna.length;
      if(percentage > maxPercentage){
        maxPercentage = percentage;
        maxI = i;
        maxJ = j;
      }  // END OF IF-CASE FOR 'MAX' VALUES
    }  // END OF IF-CASE THAT CHECKS THE DIFFERENT INSTANCES
  }  // END OF SECOND FOR-LOOP
}  // END OF FIRST FOR-LOOP

console.log();
console.log();
console.log("The 2 pAequors of the pAequorArray, that are the most related are those with ids: " + pAequorArray[maxI].specimenNum + " and " + pAequorArray[maxJ].specimenNum + ".");
console.log("Max percentage = " + (100 * maxPercentage) + "%.");
console.log("DNA Chain of pAequor with id = " + pAequorArray[maxI].specimenNum);
console.log(pAequorArray[maxI].dna);
console.log("DNA Chain of pAequor with id = " + pAequorArray[maxJ].specimenNum);
console.log(pAequorArray[maxJ].dna);