The library

Programming guides that get to the point.

Understand the rule, see it run, learn the edge case, and make the decision.

All Code design JavaScript PHP Python

Code design 4 min

Learn when early returns make a function clearer, when nesting carries useful structure, and how to refactor without changing side effects.

Language-agnostic Read guide

Code design 3 min

Choose between a conditional expression and an if / else statement using result shape, side effects, nesting, and debugging—not character count.

JavaScript / PHP Read guide