play

how this works, honestly

your code is compiled by the real javac (from jdk 25), but it doesn't run on a JVM. it runs on TeaVM, which translates the bytecode to webassembly. for teaching-sized programs that's the same answer real java gives. a few things are different or missing: virtual threads, executors, keyboard input, reflection, files and the network, and catching runtime exceptions like / 0. when a program needs those, run it on a real JDK with java Main.java.

the details, and how the runtime is built, are in src/lib/java.