AI solution for JavaScript Quiz on BFE.dev
5. scope

The code will output:

5
5
0
1
2
3
4

The first for loop uses a var declaration for i, which has function scope and is hoisted to the top of the function. As a result, when the setTimeout callbacks are executed, they all refer to the same i value, which is 5 at the end of the loop.

The second for loop uses a let declaration for i, which has block scope and is not hoisted. As a result, each iteration of the loop creates a new i variable with a new value that is captured by the corresponding setTimeout callback. Therefore, the callbacks output 0, 1, 2, 3, 4 in sequence.