המרה של אקסל למערך וממערך חזרה לאקסל בעזרת JS

loto.xhttpGetCsv = function() {
    var xhttp = new XMLHttpRequest();
    var data;
    xhttp.onreadystatechange = function() {
        if (this.readyState == 4 && this.status == 200) {
            data = this.responseText;
            loto.init(data);
        }

    }
    xhttp.open("GET", 'Lotto.csv', true);
    xhttp.send();
}
loto.xhttpGetCsv();

loto.init = function(data) {
    // -------------- convert text to object array ------
    var text2arr = data.trim().split('\n');
    text2arr = text2arr.map(item => {
        return item.split(','); // [1234,16/4/2015,1,2,3,4,5,6,7]
    }).map(item => {
        return {
            lotoNum: item[0],
            date: item[1],
            numbers: item.slice(2, 8),
            extra: item[8],
        }
    });
}

var data = [
    ["Col1", "Col2", "Col3", "Col4"],
    ["Data", 50, 100, 150],
    ["Data", -50, -20, '100%'],
];

loto.exportToCsv = function() {
    var CsvString = "";
    data.map(item => {
        item.map(subItem => {
            CsvString += subItem + ',';
        });
        CsvString += "\n";
    });
    CsvString = "data:application/csv," + encodeURIComponent(CsvString);
    var anchor = document.createElement("A");
    anchor.setAttribute("href", CsvString);
    anchor.setAttribute("download", "somedata.csv");
    document.body.append(anchor);
    anchor.click();
}