Adobe Illustrator - multi artboards

//Documentation: https://ai-scripting.docsforadobe.dev/jsobjref/Document/#documentartboards

//How to alert: alert("Hello world!")
//How to confirm: confirm ("Are you sure?")

function showCustomDialog() {
    var dlg = new Window("dialog", "Custom Settings");

    dlg.add("statictext", undefined, "Number of columns:");
    var colInput = dlg.add("edittext", undefined, "9");
    colInput.characters = 10;

    dlg.add("statictext", undefined, "Size:");
    var sizeInput = dlg.add("edittext", undefined, "50");
    sizeInput.characters = 10;

    dlg.add("statictext", undefined, "Spacing:");
    var spacingInput = dlg.add("edittext", undefined, "20");
    spacingInput.characters = 10;

    dlg.add("statictext", undefined, "Names (comma separated):");
    var namesInput = dlg.add("edittext", undefined, "", {multiline: true, scrolling: true});
    namesInput.preferredSize = [300, 120];

    var btnGroup = dlg.add("group");
    btnGroup.alignment = "right";
    var okBtn = btnGroup.add("button", undefined, "OK", {name: "ok"});
    var cancelBtn = btnGroup.add("button", undefined, "Cancel", {name: "cancel"});

    if (dlg.show() == 1) {
        var numColumns = parseInt(colInput.text, 10);
        var size = parseInt(sizeInput.text);
        var spacing = parseInt(spacingInput.text);
        var names = namesInput.text;

        return {columns: numColumns, size: size, names: names, spacing: spacing};
    } else {
        alert("Canceled.");
        return null;
    }
}

var doc = app.activeDocument;

var settings = showCustomDialog();

var colsCount = settings["columns"];
var artboardSize = settings["size"];
var artboardNamesStr = settings["names"];
var pad = settings["spacing"];

var x = 0;
var y = 0;
var artboardCounter = 0;

var artboardNamesArray = artboardNamesStr.split(",");
for(artboardIndex in artboardNamesArray){
	var artboardName = artboardNamesArray[artboardIndex];
	doc.artboards.add([x, -y, new UnitValue(x + artboardSize, "px"), -new UnitValue(y + artboardSize, "px")]);
	var lastArtboard = doc.artboards[doc.artboards.length - 1];
	lastArtboard.name = artboardName;

	artboardCounter += 1;
	x = x + artboardSize + pad;

	if(artboardCounter >= colsCount) {
		artboardCounter = 0;
		x = 0
		y = y + artboardSize + pad;
	}
}

app.redraw();