6 · Advanced · lesson 33 of 41
Threads & Runnable
Multiple flows of execution inside one JVM.
Java
Thread t = new Thread(() -> {
for (int i = 0; i < 5; i++)
System.out.println("tick " + i);
});
t.start(); // runs concurrently
t.join(); // wait for itTIP
The 3D scene shows two threads racing on a shared counter — watch it lose updates without synchronization.
Loading 3D scene…
Key takeaways
- ✓start() spawns; run() would be sequential.
- ✓Multiple threads share heap objects — that's where the trouble starts.