var vs let in setTimeout (Closure)

What is the output of the following code? What changes if we use let instead of var?

javascript for (var i = 0; i < 5; i++) { setTimeout(() => console.log(i), 100); } console.log(i);

Expected Understanding:

• var is function-scoped, let is block-scoped
• How closures capture variables
• Event loop and setTimeout behavior

With var:

• First prints: 5 (synchronously)
• Then prints: 5, 5, 5, 5, 5 (after 100ms)
• Because var i is hoisted and all callbacks share the same i

With let:

• First prints: ReferenceError (i is not defined outside loop) OR just the setTimeout outputs
• Then prints: 0, 1, 2, 3, 4 (after 100ms)
• Because let i creates a new binding for each iteration