I was asked a question similar to this for Blinkit's interview

this is classic race condition, you can't be sure that 9 is printed after 1, maybe global queue starts implementing first async block right away and prints 2 after 1

Awesome.

Nice

Why did 8 come second last? Is 8 in the same thread(global) as 2 & 4. Can you please clarify?

import Foundation func testDispatch() { print ("1") DispatchQueue.global().async{ print("2") DispatchQueue.main.async{ print("3") } print("4") DispatchQueue.main.sync{ print("5") } DispatchQueue.main.async{ print ("6") DispatchQueue.main.sync{ print ("7") } } print ("8") } print ("9") } testDispatch()