Coding Interview Question : Output of Code snippet

What will be output of following code:

Example 1:

const b = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

for (let i = 0; i < 10; i++) {

setTimeout(() => console.log(b[i]), 1000);

}

for (var i = 0; i < 10; i++) {

setTimeout(() => console.log(b[i]), 1000);

}

output:

1

2

3

4

5

6

7

8

9

10

undefined

undefined

undefined

undefined

undefined

undefined

undefined

undefined

undefined

undefined