/**
 * Array.indexOf
 */
function indexOf(arr, item, fromIndex = 0) {
    if (arr == null) {
        return -1;
    }

    const len = arr.length;
    let i = fromIndex < 0 ? len + fromIndex : fromIndex;
    while (i < len) {
        // we iterate over sparse items since there is no way to make it
        // work properly on IE 7-8. see #64
        if (arr[i] === item) {
            return i;
        }

        i++;
    }

    return -1;
}

export default indexOf;