Barcode Generator

function barcode(arr, marr) {
    let start = Number(arr);
    let end = Number(marr);
    start_first = Number(Math.floor(start / 1000));
    start_second = Number(Math.floor((start / 100) % 10));
    start_third = Number(Math.floor((start / 10) % 10));
    start_fourth = Number(Math.floor(start % 10));

    end_first = Number(Math.floor(end / 1000));
    end_second = Number((Math.floor(end / 1000) % 10));
    end_third = Number((Math.floor(end / 10) % 10));
    end_fourth = Number(Math.floor(end % 10));

    for (let num_1 = start_first; num_1 <= end_first; num_1++) {
        for (let num_2 = start_second; num_2 <= end_second; num_2++) {
            for (let num_3 = start_third; num_3 <= end_third; num_3++) {
                for (let num_4 = start_fourth; num_4 <= end_fourth; num_4++) {
                    if (num_1 % 2 !== 0 && num_2 % 2 !== 0 && num_3 % 2 !== 0 && num_4 % 2 !== 0) {
                        console.log(`${num_1}${num_2}${num_3}${num_4}`);
                    }
                }
            }
        }
    }
}
barcode(2345,
    6789);