In the following code why is i treated as a string? I have to multiple it by 1 to get it to convert back to a number.

```
  getPositionInArray(value, array) {
    console.log('array = ', array);

    let i = 0; // why is i a string?
    for (i in array) {
      if (array[i].toLowerCase() === value) {
        let positionOnUI = i * 1 + 1; // why can't I use i + 1?
        return positionOnUI;
      }
    }
    return null;
  }

```