Show multiple errors by toastr

i'm trying to show multiple error messages in view by toastr , for user register page.

I passed a list of error messages to View with TempData["errors"]

but i don't know how to show a list of string (for errors)

I did this for a successful message and the code is as follows

register.cshtml

@if (TempData["success"] != null)
    {
<script>
    $(document).ready(function() {

        var message = '@(TempData["success"])';

        toastr.options = {
            "rtl": true,
            "closeButton": false,
            "newestOnTop": false,
            "progressBar": false,
            "positionClass": "toast-top-left",
            "preventDuplicates": true,
            "onclick": null,
            "showDuration": "300",
            "hideDuration": "1000",
            "timeOut": "5000",
            "extendedTimeOut": "1000",
            "showEasing": "swing",
            "hideEasing": "linear",
            "showMethod": "fadeIn",
            "hideMethod": "fadeOut"
        };

        toastr.success(message);


    });

My suggestion is that:

You could turn the list to string in your controller as follow:

var err = new List<string>() { "error1", "error2", "error3" };
var er = string.Join(",", err.ToArray());
 TempData["errors"] = er;

then replace ","with <br/> in your javascript codes as follow :

var message1 = '@TempData["errors"]';
var message2 = message1.replaceAll(',', '<br/>');
toastr.error(message2, 'Errors');

Result:

but if you turn the list to string as follow :

controller:

var err = new List<string>() { "error1", "error2", "error3" };
var er1 = string.Join("<br/>", err.ToArray());
TempData["error?"] = er1;

Js:

var message3 = '@TempData["error?"]';
toastr.error(message3, 'Errors');

Result:

If you want send Individual error message: controller:

var err = new List<string>() { "error1", "error2", "error3" };
TempData["error!"] = err;

Js:

var message4 = @Html.Raw(Json.Serialize(TempData["error!"]));
 message4.forEach(x => toastr.error(x));

Result: