Definition - Multithreading:Multithreading is a type of execution model that allows multiple threads to exist within the context of a process such that they execute independently but share their process resources.In that sense JavaScript is totally multithreaded thing:
let Ar; Ar = [] function multiapp(ar,w,n) { ar.clear; for (let i = 0; i < n; i++) setTimeout(function(){ar.push(w)},i); }+function fn() { //Thread 1 setTimeout(() => multiapp(Ar,1,10),100) //Thread 2 setTimeout(() => multiapp(Ar,2,10),100) }() setTimeout(function(){console.log('Ar(1) = ', Ar.filter((i) => i == 1).length,'Ar(2) = ', Ar.filter((i) => i == 2).length,' Ar = ',Ar)},2000);//Ar(1) = 10 Ar(2) = 10 Ar = [ 1, 1, 2, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2 ]`Apparently thread 1 starts and executes its own stack, independently of thread 2. Two threads share access to the same context object instance Ar and modify it in unknown fashion. Behaves exactly as Java with atomic primitives.