JavaScript Comments

Comments are notes for people. The computer skips them.

They help you remember why you wrote something.

Think of sticky notes on a toy box. The toys still work. The notes just explain.

Single line comments

Start a short note with //.

Everything after that on the same line is ignored.

Multi line comments

Wrap longer notes in /* and */.

You can write many lines inside.

Explain why, not only what

Code already shows what happens.

A good comment explains the reason.

Why did we choose this number? Why this name?

Turn code off for a moment

You can comment out a line while you test.

That is like covering a light switch with tape for a minute.

Keep comments fresh

Old comments that lie are worse than no comments.

If you change the code, update the note too.

Tip: Write comments for the next learner. Future you counts as a learner.