How to fix javascript .toFixed is not a Function error

Question

Here I am trying to add two decimal values in line var totalSum = (grandTotal + getShippingCost).toFixed(3); and put the value in var getSumTd = $("tr#sumTr").find("span#sumSpan");.

But the problem is that var totalSum = (grandTotal + getShippingCost).toFixed(3); throws an error saying Uncaught TypeError: value.toFixed is not a function.

Any help with my code will be great help.

Below is my script

<script>
$('button#value-plus').on('click', function () {
    debugger;
    var divUpd = $(this).closest("tr").find('#qnty');
    var subtotalcontainer = $(this).closest("tr").find('span#subtotal');
    var mainGrandTotalcontainer = $("tr#mainGtTr").find("#mainGt");
    var mainGtVal = parseFloat($("tr#mainGtTr").find('span#shippingCost').text());

    var getSumTd = $("tr#sumTr").find("span#sumSpan");
    var getShippingCost = parseFloat($("tr#mainGtTr").find('span#mainGt1').text());

    var bklId = $(this).closest("tr").find('#pid').val();
    var url = "/Product/incrementcart";
    $.getJSON(url, { prdid: bklId }, function (data) {
        debugger;
        divUpd.val(data.qty);
        var subTotal = data.qty * data.price;
        subtotalcontainer.text(subTotal.toFixed(2));

        var grandTotal = (mainGtVal + data.price).toFixed(3);
        mainGrandTotalcontainer.text(grandTotal);

        var totalSum = (grandTotal + getShippingCost).toFixed(3);
        getSumTd.text(totalSum);

    }).success(function () {
        debugger
        var url = "/Product/cartupdate";
        $.get(url, function (data) {
            debugger;
            $(".shopping_button").html(data);
        })
    });
});   

Below is my HTML

     <tbody>
                        @foreach (var item in Model)
                        {
                            <tr>
                                @Html.HiddenFor(model => item.ProductId, htmlAttributes: new { @id = "pid" })
                                <td data-title="Product Image &amp; name" class="t_md_align_c">
                                    <img src="images/quick_view_img_10.jpg" alt="" class="m_md_bottom_5 d_xs_block d_xs_centered">
                                    <a href="#" class="d_inline_b m_left_5 color_dark">@Html.DisplayFor(modelItem => item.ProductName)</a>
                                </td>
                                <td data-title="Stock">
                                    @Html.DisplayFor(modelItem => item.Instock)
                                </td>
                                <td data-title="Price">
                                    <p class="f_size_large color_dark">[email protected](modelItem => item.ProductPrice)</p>
                                </td>
                                <td data-title="Quantity">
                                    <div class="clearfix quantity r_corners d_inline_middle f_size_medium color_dark m_bottom_10">
                                        <button class="bg_tr d_block f_left" data-direction="down" id="value-minus">-</button>
                                        <input type="text" name="" id="qnty" readonly value="@item.Quantity" class="f_left">
                                        <button class="bg_tr d_block f_left" data-direction="up" id="value-plus">+</button>
                                    </div>
                                </td>
                                <td data-title="Subtotal">
                                    <p class="f_size_large fw_medium scheme_color">$<span id="subtotal">@Html.DisplayFor(modelItem => item.Total)</span></p>
                                </td>
                                <td data-title="Remove">
                                    <a href="#" class="color_dark"><i class="fa fa-times f_size_medium m_right_5"></i>Remove</a><br>
                                </td>
                            </tr>
                        }
                        <tr id="mainGtTr">
                            <td colspan="4" class="v_align_m d_ib_offset_large t_xs_align_l">
                                <div class="d_ib_offset_0 d_inline_middle half_column d_xs_block w_xs_full m_xs_bottom_5">
                                    <button class="button_type_6 bg_scheme_color f_size_large r_corners tr_all_hover color_light m_bottom_20">Check Out </button>
                                </div>
                                <p class="fw_medium f_size_large t_align_r scheme_color p_xs_hr_0 d_inline_middle half_column d_ib_offset_normal d_xs_block w_xs_full t_xs_align_c">Grand Total:</p>
                            </td>
                            <td colspan="2" class="v_align_m">
                                <p class="fw_medium f_size_large scheme_color m_xs_bottom_10">$<span id="mainGt">@ViewBag.SubTotal</span></p>
                                <p style="font-style:oblique">Include <i class="fa fa-rupee"></i> <span id="shippingCost">@ViewBag.ShipingCost</span> shipping cost</p>
                            </td>
                        </tr>
                        @{
                            var sum = ViewBag.SubTotal + ViewBag.ShipingCost;
                        }
                        <tr id="sumTr">
                            <td>
                                <span id="sumSpan">@sum</span>
                            </td>
                        </tr>
                    </tbody>

Answer 1

toFixed() method formats a number. The current value is of type string and instead of arithmetic addition, string concatenation is happening. Convert those to number before adding:

Change:

var totalSum = (grandTotal + getShippingCost).toFixed(3);

To

var totalSum = (Number(grandTotal) + Number(getShippingCost)).toFixed(3);

Answer 2

Only float, int value have toFixed. controle your variable and see which type are they.

console.log(("4" + 5).toFixed(3)); // error

console.log((5 + 5).toFixed(3)); // yeep its working

Answer 3

toFixed method is not available on non-number values. you need to parse value to Number first than you can use toFixed method.

let str = `123.123456`

console.log(Number(str).toFixed(3))
console.error(str.toFixed(3))