如何对 JavaScript 中具有相同类名的表中的所有列求和？

Question

I am trying to sum a price in a table, all the prices in the <td> have the same class name and I'd like to sum them up on a button click. I would eventually like to calculate the quantity into the total as well. This is what I have so far:

 function sumAmounts() { var sum = 0; var listPriceTotal = $('.txtListPrice').each(function() { sum += parseFloat($(this).html); // Or this.innerHTML, this.innerText }); document.getElementById("txtTotal").value = listPriceTotal; } document.getElementById("addTotals").addEventListener("click", () => { sumAmounts(); });

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <table id="table"> <tr> <th><label>SKU</label></th> <th><label>Retail Price</label></th> <th><label>List Price</label></th> <th><label>Product Name</label></th> <th><label>Quantity</label></th> </tr> <tr> <td class="txtSKU">1234</td> <td class="txtRetailPrice">12.50</td> <td class="txtListPrice">11.75</td> <td class="txtProductName">product 1</td> <td class="txtQuantity"><input type="text"> </td> </tr> <tr> <td class="txtSKU">12222</td> <td class="txtRetailPrice">14.50</td> <td class="txtListPrice">9.75</td> <td class="txtProductName">product 2</td> <td class="txtQuantity"><input type="text"> </td> </tr> <tfoot> <th><label id="lblTotal">Total:</label><input type="text" name="txtTotal" id="txtTotal"> <input type="button" value="Add" id="addTotals"> </th> </tfoot> </table>

Answer 1

There's two issues in your code. Firstly you're trying to set a jQuery object as the value of the input , which is why you see [Object object] in the field. You need to set the value to sum .

The second issue is that you're supplying the html method reference to parseFloat() , not the actual html() value. With both of those addressed, the code works:

 function sumAmounts() { var sum = 0; $('.txtListPrice').each(function() { sum += parseFloat($(this).html()); }); document.getElementById("txtTotal").value = sum; } document.getElementById("addTotals").addEventListener("click", () => { sumAmounts(); });

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <table id="table"> <tr> <th><label>SKU</label></th> <th><label>Retail Price</label></th> <th><label>List Price</label></th> <th><label>Product Name</label></th> <th><label>Quantity</label></th> </tr> <tr> <td class="txtSKU">1234</td> <td class="txtRetailPrice">12.50</td> <td class="txtListPrice">11.75</td> <td class="txtProductName">product 1</td> <td class="txtQuantity"><input type="text"> </td> </tr> <tr> <td class="txtSKU">12222</td> <td class="txtRetailPrice">14.50</td> <td class="txtListPrice">9.75</td> <td class="txtProductName">product 2</td> <td class="txtQuantity"><input type="text"> </td> </tr> <tfoot> <th> <label id="lblTotal">Total:</label> <input type="text" name="txtTotal" id="txtTotal"> <input type="button" value="Add" id="addTotals"> </th> </tfoot> </table>