One of the unintuitive aspects of p5 that beginners often make is using
p5 globals in their “top level” code, i.e. outside of
Believe it or not, this sketch doesn’t work, and will result in the following error being thrown:
ReferenceError: color is not defined
It’s hard to detect such errors with 100% accuracy, but in #1130 I added some code that attempts to detect it, and in #1256 I improved on it so that the following console message is now displayed when the above sketch runs:
Did you just try to use p5.js's color() function? If so, you may want to move it into your sketch's setup() function. For more details, see: https://github.com/processing/p5.js/wiki/Frequently-Asked-Questions#why-cant-i-assign-variables-using-p5-functions-and-variables-before-setup
I wish there was an easy way to get feedback on whether users actually find this message helpful. I can think of a few solutions to this, but more on that in a future blog post!