importance: 4

---

# Which values does the while loop show?

For every loop iteration, write down which value it outputs and then compare it with the solution.

Both loops `alert` the same values, or not?

1. The prefix form `++i`:

    ```js
    let i = 0;
    while (++i < 5) alert( i );
    ```
2. The postfix form `i++`

    ```js
    let i = 0;
    while (i++ < 5) alert( i );
    ```