Hello, this is my first blog post on this site. I'm planning to have some content on here apart from Medium. So, here goes.

I've been thinking of getting back into web development. Specifically, web app development consisting of Node.JS and the rest of the javascript world. So, I've decided to make small websites here and there just to refresh my memory. In this post, I will talk about a bug I encountered when I was building a stopwatch.

This is the code for the main functionality controlling the stopwatch.

I thought it was okay until this happened.

As you can see, the seconds is okay. But the minutes and hours are not. My code appended "0"s each time it passes through this part here.

When I looked at the code, I expected minutes to remain at 0 since "0" + minutes is equals to 0. And I also expected minutes to go "00", "00" and so on and so forth.

So, when I look at this behaviour, I realise only strings have this behaviour, not Numbers.

I added some console logs to the code and checked for type.

And this was what showed up.

Now it is starting to make sense. That was why it appended the "0" instead of adding.

In conclusion, I still do not know what to expect when I add 2 variables together. But now, I know a little more.