Hackerrank Solution: switch in JavaScript

In this post I’m going to show you one possible solution of one of the 10 Days of JavaScript challenges from Hackerrank. We’re going to use switch statement to return a letter depending on the first letter of provided string.


Full description of the challenge: 10 Days of JavaScript. Day 2: switch. I really recommend registering and trying these challenges by yourself.

“Complete the getLetter(s) function in the editor. It has one parameter: a string, s, consisting of lowercase English alphabetic letters (i.e., a through z). It must return ABC, or D depending on the following criteria:

  • If the first character in string is in the set {a, e, i, o, u}, then return A.
  • If the first character in string is in the set {b, c, d, f, g} , then return B.
  • If the first character in string is in the set {h, j, k, l, m} , then return C.
  • If the first character in string is in the set {n, p, q, r, s, t, v, w, x, y, z}, then return D.”

Solution and explanation

The first solution is simple and self explanatory:

But it’s also not pretty. I mean it’s not terrible but I’m not happy with it. I would rather use something shorter. Also, it would be nice if sets of letters where grouped (so I don’t have to provide every letter separately). It can be achieved by below code:

The tricky thing of course is switch(true). It makes the switch statement look for the first “true” case. It’s bit confusing and my impression is that it’s a bit forced. For that you could use if-else which feels like a natural solution for this kind of problem. The challenge was about switch usage though, so I’ve used switch.

. . .

Yes, this stupid code works 💛

Leave a Comment