Algorithm 101: 3 Ways to Find Hamming Distance

#algorithms #javascript #string #distance

According to Wikipedia, the Hamming distance between two strings of equal length is the number of positions at which the corresponding symbols are different. In other words, it measures the minimum number of substitutions required to change one string into the other, or the minimum number of errors that could have transformed one string into the other.


hammingDistance("part", "path"); // 2

hammingDistance("ebere", "samson"); // 'unequal word lengths'

In how many ways can you check for the hamming distance of two given strings of equal length? When was the last time you used do...while...loop and while...loop?

This article presents us with 3 ways to check for hamming distance. Let's get to it.

Prerequisite

This article assumes that you have basic understanding of javascript's string and array methods.

Let's determine the hamming distance of two given strings using:

for...loop, if...statement and toLowerCase()

      function hammingDistance(word, matchingWord) {
        let count = 0;

        if (word.length === matchingWord.length) {
          for (let i = 0; i <= word.length; i++) {
            if (word.toLowerCase()[i] !== matchingWord.toLowerCase()[i]) {
              count++;
            }
          }

          return count;
        }
        return "unequal word lengths";
      }

while...loop, if...statement and toLowerCase()

      function hammingDistance(word, matchingWord) {
        let count = 0;
        let i = 0;

        if (word.length === matchingWord.length) {
          while (i <= word.length) {
            if (word.toLowerCase()[i] !== matchingWord.toLowerCase()[i]) {
              count++;
            }
            i++;
          }

          return count;
        }
        return "unequal word lengths";
      }

do...while...loop if...statement and toLowerCase()

      function hammingDistance(word, matchingWord) {
        let count = 0;
        let i = 0;

        if (word.length === matchingWord.length) {
          do {
            if (word.toLowerCase()[i] !== matchingWord.toLowerCase()[i]) {
              count++;
            }
            i++;
          } while (i <= word.length);

          return count;
        }
        return "unequal word lengths";
      }

Conclusion

There are many ways to solve problems programmatically. You are only limited by your imagination. I will love to know other ways you solved yours in the comment section.

If you have questions, comments or suggestions, please drop them in the comment section.