This should play if your Web browser has WebAssembly enabled (most do). Most examples will play unless they need to load files. The first time you click Play, Csound will spend a few seconds loading, then play. You can edit this code and replay it.
; Select audio/midi flags here according to platform -n ;no sound output ; sr = 44100 ; ksmps = 32 ; nchnls = 2 0dbfs = 1 instr 1 ;shows what init does kinit init 0 kinit = kinit + 1 printk .1, kinit endin instr 2 ;shows what an assignment does knoinit = 0 knoinit = knoinit + 1 printk .1, knoinit endin ;play one second each i1 0 1 i2 2 1 e