Why is this giving error in this one? // https://ide.codingblocks.com/s/263895 // And Also Please tell does it affects when we do app.listen() on top or at bottom? // Please tell about this issue?s

#1

Why is this giving error in this one?
// https://ide.codingblocks.com/s/263895
// And Also Please tell does it affects when we do app.listen() on top or at bottom?
// Please tell about this issue?s