About FirstHack Learn

Most programming resources are written by people who have forgotten what it is like to not know anything. They skip the step where you do not yet know what a compiler is, or why your code has to be indented, or what the error message is actually telling you.

Everything here assumes you are starting from zero, explains why things work rather than only how, and lets you run every example without installing anything.

When you press Run, your program is sent to an isolated sandbox service that executes it in a throwaway container with its own CPU, memory and time limits. It never runs on this website's server. Your code is not stored, not shown to anyone, and not used for anything else. Submissions to practice problems are saved so you can see your own history.