This detailed tutorial shows how to implement pure functions in JavaScript that are deterministic and referentially transparent, and create no side effects.

IDG For starters, let’s create a function that draws a watercolor spot with a given position, radius, and hue. P5.js gives us a function to draw an ellipse that we already used last week. By ...

Full stop. If you want more examples or further reading, check out the chapter on higher-order functions in “ Eloquent JavaScript ” by Marijn Haverbeke. Questions or comments?

If you’ve gone through Thau’s basic JavaScript tutorial (or you already know a bunch about the subject), Thau’s advanced JavaScript course is just for you. In the previous tutorial, Thau ...