Try This Reaction Time Challenge

Ajouté : 2026-06-03

[00:00:00]Let's test your reaction time. When the box turns green, tap the screen as fast as you can. Ready?

[00:00:07]In 3 2 1.

[00:00:17]Here's how this code works. When I press start, this line waits a random number of seconds before doing anything. Then the box changes from [music] red to green.

[00:00:26]At the exact same moment, the code saves the current time. When I click the box, the code checks the time again.

[00:00:32]It subtracts the two times to find how long it took me to react.

[00:00:36]That's how this program measures reaction time using just a few lines of JavaScript. Every app, game, [music] and piece of technology is built from simple systems like this.

[00:00:45]Subscribe to Stem Simplified to see how they work.