Hamming Distance - PhillyDev Slack #daily_programmer - 20170307

dp20170307.js

/*
Calculate the Hamming Distance between 2 DNA strands.
*/
const dna1 = "GAGCCTACTAACGGGAT";
const dna2 = "CATCGTAATGACGGCCT";

function hammingDistance1(strand1, strand2) {
  let count = 0;
  if (strand1 && strand2) {
    if (strand1.length == strand2.length) {
      strand1 = strand1.split('');
      strand2 = strand2.split('');
      strand1.forEach(function(point, i) {
        if (point !== strand2[i]) {
          count++;
        }
      });
    } else {
      console.log("WARNING: DNA strands should be the same length.");
    }
  } else {
    console.log("WARNING: Need 2 strands of DNA to test.");
  }
  return count;
}

function hammingDistance2(strand1, strand2) {
  let count = 0;
  if (strand1 && strand2) {
    count = strand1.length;
    if (strand1.length == strand2.length) {
      for (let i = 0; i < strand1.length; i++) {
        if (strand1.charAt(i) == strand2.charAt(i)) {
          count--;
        }
      }
    } else {
      console.log("WARNING: DNA strands should be the same length.");
    }
  } else {
    console.log("WARNING: Need 2 strands of DNA to test.");
  }
  return count;
}

hammingDistance = hammingDistance1;

let count = hammingDistance(dna1, dna2);
console.log(count);