A tiny, no-nonsense Kotlin course. Real code that compiles in your browser. A certificate at the end you can actually keep.
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Print to the console and embed values in strings.
Read-only and mutable bindings — when each one fits.
Int, Double, String, Boolean — meet each one with its own example.
&& (and), || (or), and ! (not) — compose booleans into bigger conditions.
Two ways to branch — and how they relate.
for over ranges, plus modifiers like step and downTo.
Declarations, defaults, and single-expression form.
Properties, methods, data classes, and mutable state.
Lists, plus the workhorses map and filter.
Nullable types, the Elvis operator, and safe calls.
Anonymous functions, higher-order functions, and trailing lambdas.
Two classic warm-ups before you wrap up the course.
Real Kotlin, compiled in your browser. No installs.
Edit, run, break, fix. Every lesson ships with runnable code.
Finish the course, download a personalised PDF certificate.