小贝子编程

如何对表列中的值求和并在删除/添加新行时更新



我正在尝试对一个特定列的值求和，但老实说我不知道该怎么做，我也想在添加或删除某些行时刷新该总值，我该怎么做？我正在尝试在 SO 上提出类似问题，但它们汇总了所有列的值，我只想对特定列执行此操作！这是我所拥有的：

function deleteRow(btn) {
var row = btn.parentNode.parentNode;
row.parentNode.removeChild(row);
}
$('#xd').click(function() {
var lines = "";
lines += '<td>3</td>';
lines += '<td>3</td>';
lines += '<td>15</td>';
lines += '<td>Credit</td>';
lines += '<td>1</td>';
lines += '<td>100.00</td>';
lines += '<td><input type="button" value="Delete" onclick="deleteRow(this)"/></td>';
$('#TableBody').append(lines);
})
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<table id="Table">
<thead>
<tr>
<td>ID</td>
<td>Code</td>
<td>Client</td>
<td>Debit/Credit</td>
<td>Quantity</td>
<td>Price</td>
<td>Options</td>
</tr>
</thead>
<tbody id="TableBody">
<tr>
<td>1</td>
<td>1</td>
<td>3</td>
<td>Debit</td>
<td>10</td>
<td>12.00</td>
<td>
<input type="button" value="Delete" onclick="deleteRow(this)" />
</td>
</tr>
<tr>
<td>2</td>
<td>2</td>
<td>12</td>
<td>Debit</td>
<td>5</td>
<td>10.00</td>
<td>
<input type="button" value="Delete" onclick="deleteRow(this)" />
</td>
</tr>
</tbody>
<tfoot id="TableFooter">
<tr>
<td colspan="4">Total</td>
<td>15</td>
<td>170.00</td>
</tr>
</tfoot>
</table>
<input type="button" id="xd" value="add row">

在上面的代码中，我手动添加了"总计"列(价格，数量)，我想在用户添加/删除行时更新总结果。

您的方法对于长期使用来说有点脆弱，但作为概念证明，这可能会有所帮助。

对数字数组求和的关键技术是使用Array.reduce，其工作原理如下：

var array = [1, 2, 6, 1, 5];
var total = array.reduce(function(total, number) {
return total + number;
}, 0);
document.write('<h1>Total: <code>' + total + '</code></h1>');

给定一个数字数组，遍历每个数字并将number添加到total，total从0开始。Array.reduce接受两个参数：一个对每个项目执行的函数和一个起始值。迭代器函数将接收两个参数，在您的情况下是运行总计和下一个数字。

有关更多详细信息，请参阅Array.reduce上的 MDN 文档。

一些提示

  • 尽可能将事情分解为更小的功能。
  • 限制全局变量的使用，但当你确实需要它们时，要干净和一致
  • 限制在 DOM 上存储数据(我稍微违反了这一点，但这只是草图代码)
  • 尝试以可重用的方式编写代码

这种方法的好处是，它可以更轻松地添加新功能/更改构建的内容。例如，如果我们编写一个泛型函数getColumnTotal(selector)，这将允许您为列的单元格指定 jQuery 选择器(例如：.priceCell)，然后您可以将其重用于其他列，例如quantity.

我假设您正在朝着一个显示所有单个订单/行的总和的总计单元格工作。为此，我们需要做的就是计算每一行的subtotal，为其添加一个新列，然后重用该getColumnTotal函数来汇总所有小计。瞧，总计。

请注意，我的代码不考虑错误，因此您可能需要处理输入无效quantity或price数据的情况。

var $tableBody = $('#TableBody');
var $totalQuantityCell = $('#totalQuantityCell');
var $totalPriceCell = $('#totalPriceCell');
var $totalGrandCell = $('#grandTotalCell');
// Add a row with random values on "Add Row" button click
$('#xd').click(addRandomRow);
function addRandomRow(event) {
var randomCode = Math.round(Math.random() * 4);
var randomClient = Math.round(Math.random() * 15);
var randomCharge = ( Math.round(Math.random()) ? 'Debit' : 'Credit' );
var randomQuantity = Math.ceil(Math.random() * 5);
var randomPrice = Math.ceil(Math.random() * 100).toFixed(2);

addRow(randomCode, randomClient, randomCharge, randomQuantity, randomPrice);
};
// Add some rows to start
addRandomRow();
addRandomRow();
// Listen for clicks on ".deleteRowButton" within the table
$tableBody.on('click', '.deleteRowButton', function(event) {
deleteRow( $(event.target).data('row') );
updateTotals();
});
// --------------------------
function addRow(code, client, chargeType, quantity, price) {
// Create a new row element
var idNum = ( $tableBody.find('tr').length + 1 );
var rowId = 'row-' + idNum;
var $row = $('<tr id="' + rowId + '"></tr>');
// Add the table cells
$row.append('<td class="idCell">' + idNum + '</td>');
$row.append('<td class="codeCell">' + code + '</td>');
$row.append('<td class="clientCell">' + client + '</td>');
$row.append('<td class="chargeTypeCell">' + chargeType + '</td>');
$row.append('<td class="quantityCell">' + quantity + '</td>');
$row.append('<td class="priceCell">' + price + '</td>');
$row.append('<td class="orderTotalCell">' + getSubtotal(quantity, price) + '</td>');
$row.append('<td><input type="button" value="Delete" class="deleteRowButton" data-row="#' + rowId + '" /></td>');
// Append the row to the table body
$tableBody.append($row);
updateTotals();
}
function deleteRow(rowId) {
$(rowId).remove();
}
function updateTotals() {
var totalQuantity = getColumnTotal('.quantityCell');
var totalPrice = getColumnTotal('.priceCell');
var totalOrder = getColumnTotal('.orderTotalCell');

$totalQuantityCell.text( totalQuantity );
$totalPriceCell.text( toMoney(totalPrice) );
$totalGrandCell.text( toMoney(totalOrder) );
}
/**
A standard function to calaculate the subtotal of a row, this is
where you could apply tax or other data transformations if need be.
*/
function getSubtotal(quantity, price) {
return (quantity * price).toFixed(2);
}
/**
Takes a jQuery selector, finds all matching elements for it, and totals up their contents.
It works by converting the elements list to an Array and then using Array.reduce.
@see https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce
*/
function getColumnTotal(selector) {
return Array.from( $(selector) ).reduce(sumReducer, 0);
}
/**
The reducer function that adds up a running total. This function parses the innerHTML content
of an element and converts it to a number so math works on it.
*/
function sumReducer(total, cell) {
return total += parseInt(cell.innerHTML, 10);
}
function toMoney(number) {
return '$' + number.toFixed(2);
}
#TableHead td {
border-bottom: 1px #000 solid;
}
.orderTotalCell,
#grandTotalCell,
#totalPriceCell {
text-align: right;
}
#TableFooter tr:first-child td {
border-top: 1px #000 solid;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<table id="Table">
<thead id="TableHead">
<tr>
<td>ID</td>
<td>Code</td>
<td>Client</td>
<td>Debit/Credit</td>
<td>Quantity</td>
<td>Price</td>
<td>Order Total</td>
<td>Options</td>
</tr>
</thead>
<tbody id="TableBody">
</tbody>
<tfoot id="TableFooter">
<tr>
<td colspan="4">Sub-Total</td>
<td id="totalQuantityCell">&ndash;</td>
<td id="totalPriceCell">&ndash;</td>
<td id="grandTotalCell">&ndash;</td>
</tr>
</tfoot>
</table>
<input type="button" id="xd" value="add row">

有很多答案，但这里有一种更面向对象的方法。

function row(Id, Code, Client, DebitCredit, Quantity, Price) {
this.Id = Id;
this.Code = Code;
this.Client = Client;
this.DebitCredit = DebitCredit;
this.Quantity = Quantity;
this.Price = Price;
}
function model() {
this.rows = [];
}
var mymodel = new model();
$(document).ready(function() {
mymodel.rows.push(new row(1, 1, 3, 'Debit', 10, 12))
mymodel.rows.push(new row(2, 2, 12, 'Debit', 5, 10))
draw();
$("body").on("click", ".delete", function() {
var id = $(this).data('id');
for (i = 0; i < mymodel.rows.length; i++) {
console.log(mymodel.rows[i].Id);
if (mymodel.rows[i].Id == id) {
mymodel.rows.splice(i, 1);
}
}
draw();
});
$('#add').click(function() {
mymodel.rows.push(new row(
$('#Id').val(),
$('#Code').val(),
$('#Client').val(),
'Debit',
Number($('#Quantity').val()),
Number($('#Price').val())
))
draw();
});
})
function draw() {
$('tbody').empty();
var totalQuantity = 0;
var totalPrice = 0;
$.each(mymodel.rows, function(i, row) {
totalQuantity += row.Quantity;
totalPrice += row.Price;
var myrow = '<tr>'
$.each(row, function(key, value) {
myrow += '<td>' + value + '</td>'
});
myrow += '<td><input type="button" class="btn btn-danger delete" data-id="' + row.Id + '" value="X"/></td>'
myrow += '<tr>'
$('tbody').append(myrow);
});
$('#totalQuantity').text(totalQuantity)
$('#totalPrice').text(totalPrice)
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
<!-- Optional theme -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap-theme.min.css" integrity="sha384-rHyoN1iRsVXV4nD0JutlnGaslCJuC7uwjduW9SVrLvRYooPp2bWYgmgJQIXwl/Sp" crossorigin="anonymous">
<table class="table table-condensed">
<thead>
<tr>
<td>ID</td>
<td>Code</td>
<td>Client</td>
<td>Debit/Credit</td>
<td>Quantity</td>
<td>Price</td>
<td>Delete</td>
</tr>
</thead>
<tbody>
</tbody>
<tfoot>
<tr>
<td colspan=7>Total Quantity:
<span id="totalQuantity"></span> Total Price:
<span id="totalPrice"></span>
</td>
</tr>
</tfoot>
</table>
<form class="form-inline">
<div class="form-group">
<label for="id">Id:</label>
<input type="number" class="form-control" id="Id">
</div>
<div class="form-group">
<label for="Code">Code:</label>
<input type="number" class="form-control" id="Code">
</div>
<div class="form-group">
<label for="Client">Client:</label>
<input type="number" class="form-control" id="Client">
</div>
<div class="form-group">
<label for="Quantity">Quantity:</label>
<input type="number" class="form-control" id="Quantity">
</div>
<div class="form-group">
<label for="Price">Price:</label>
<input type="number" class="form-control" id="Price">
</div>
<input type="button" class="btn btn-info" value="add" id="add" />
</form>

你失踪了：

添加新

行时

<tr> </tr>
标记。另外，只需添加一个将">数量">和"价格">相加的类。这是一个可行的解决方案。希望对您有所帮助！

function deleteRow(btn) {
var row = btn.parentNode.parentNode;
row.parentNode.removeChild(row);
sumOfColumns();
}
function sumOfColumns(){
var totalQuantity = 0;
var totalPrice = 0;
$(".someClass").each(function(){
totalQuantity += parseInt($(this).html());
$(".someTotalClass").html(totalQuantity);
});
$(".classPrice").each(function(){
totalPrice += parseInt($(this).html());
$(".someTotalPrice").html(totalPrice);
});
}
$(document).ready(function () {

$('#xd').click(function() {
var lines = "";
lines += '<tr>';
lines += '<td>3</td>';
lines += '<td>3</td>';
lines += '<td>15</td>';
lines += '<td>Credit</td>';
lines += '<td class = "someClass">1</td>';
lines += '<td class = "classPrice">100.00</td>';
lines += '<td><input type="button" value="Delete" onclick="deleteRow(this)"/></td>';
lines += '</tr>';
$('#TableBody').append(lines);
sumOfColumns();
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<table id="Table">
<thead>
<tr>
<td>ID</td>
<td>Code</td>
<td>Client</td>
<td>Debit/Credit</td>
<td>Quantity</td>
<td>Price</td>
<td>Options</td>
</tr>
</thead>
<tbody id="TableBody">
<tr>
<td>1</td>
<td>1</td>
<td>3</td>
<td>Debit</td>
<td class = "someClass">10</td>
<td class = "classPrice">12.00</td>
<td>
<input type="button" value="Delete" onclick="deleteRow(this)" />
</td>
</tr>
<tr>
<td>2</td>
<td>2</td>
<td>12</td>
<td>Debit</td>
<td class = "someClass">5</td>
<td class = "classPrice">10.00</td>
<td>
<input type="button" value="Delete" onclick="deleteRow(this)" />
</td>
</tr>
</tbody>
<tfoot id="TableFooter">
<tr>
<td colspan="4">Total</td>
<td class = "someTotalClass">15</td>
<td class = "someTotalPrice"">170.00</td>
</tr>
</tfoot>
</table>
<input type="button" id="xd" value="add row">

您可以创建一个函数来计算总计，并在添加每行后和页面加载时调用它(如果您有一些初始值)。

function setTotal()
{
var totalPrice=0;
var totalQty=0;
$('#TableBody').find('tr').each(
function(){
totalQty +=parseFloat($(this).find('td').eq(4).text());
totalPrice +=parseFloat($(this).find('td').eq(5).text());
//console.log(totalPrice);
});
$('#TableFooter').find('tr td').eq(1).text(totalQty);
$('#TableFooter').find('tr td').eq(2).text(totalPrice);
}
$(function(){
setTotal();
})

$('#ID').find('tr') 将找到 ID 为 'ID' 的表的所有行。 然后使用每个函数遍历每个 TR。然后在每一行中，您以类似的方式找到所有 td，并使用 eq 函数获得特定的 td。eq 获取元素的索引。

这是运行小提琴手：https://jsfiddle.net/8a4umvdr/

您的脚本中有几个缺陷，我想引导您完成这些缺陷，以便您可以更好地理解该过程：

  1. 避免使用内联 JS。如果要动态绑定事件，可以改用.on()。由于该表存在于 DOM ready 上，因此您可以使用$('#Table').on(...)来侦听删除按钮上的单击事件

  2. 将求和计算模块化为单个函数。您可以创建一个函数，例如computeSum()，每次修改表时都会调用该函数：无论是添加表行还是删除表行时。您还可以在运行时调用此函数，这样就不必使用服务器端语言来预先计算起始总和。

    • 在下面的示例中，我将获取第 5 列和第 6 列中的文本节点(由从零开始的索引4和5)，并通过在它们前面附加+将它们转换为浮点数
    • 我在打印总和时也使用了.toFixed(2)函数，因此它很好地显示了两个小数位。

  3. 修复您的 HTML 注入。请记住，要使<td>元素有效，它们必须嵌套在<tr>中。你似乎不小心漏掉了。

因此，这是您的代码片段的一个功能齐全的示例：

$(function() {
// Function to compute sum
var computeSum = function() {
// Get the total quantity and price by column index
var quantity = 0,
price = 0;

// Iterate through each row
$('#TableBody tr').each(function() {
quantity += +$(this).find('td').eq(4).text();
price += (+$(this).find('td').eq(5).text() * +$(this).find('td').eq(4).text());
});

// Update sum
$('#TableFooter td.total.quantity').text(quantity.toFixed(2));
$('#TableFooter td.total.price').text(price.toFixed(2));
};
// Use on to bind click event handlers to input buttons with delete-row action
$('#Table').on('click', 'input[type="button"][data-action="delete-row"]', function(e) {
e.preventDefault();
// Delete row
$(this).closest('tr').remove();
// Recompute sum
computeSum();
});
$('#xd').click(function() {
// Remember to wrap your cells within <tr>
var lines = "<tr>";
lines += '<td>3</td>';
lines += '<td>3</td>';
lines += '<td>15</td>';
lines += '<td>Credit</td>';
lines += '<td>1</td>';
lines += '<td>100.00</td>';
lines += '<td><input type="button" value="Delete" data-action="delete-row" /></td>';
lines += "</tr>";
// Append new table row
$('#TableBody').append(lines);
// Recompute sum
computeSum();
});

// Compute sum when starting up
computeSum();
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<table id="Table">
<thead>
<tr>
<td>ID</td>
<td>Code</td>
<td>Client</td>
<td>Debit/Credit</td>
<td>Quantity</td>
<td>Price</td>
<td>Options</td>
</tr>
</thead>
<tbody id="TableBody">
<tr>
<td>1</td>
<td>1</td>
<td>3</td>
<td>Debit</td>
<td>10</td>
<td>12.00</td>
<td>
<input type="button" value="Delete" data-action="delete-row" />
</td>
</tr>
<tr>
<td>2</td>
<td>2</td>
<td>12</td>
<td>Debit</td>
<td>5</td>
<td>10.00</td>
<td>
<input type="button" value="Delete" data-action="delete-row" />
</td>
</tr>
</tbody>
<tfoot id="TableFooter">
<tr>
<td colspan="4">Total</td>
<td class="total quantity">15</td>
<td class="total price">170.00</td>
</tr>
</tfoot>
</table>
<input type="button" id="xd" value="add row">

进一步的改进

您可以对上面的代码进行一些小的改进，但它们被认为是非关键任务的，因此我没有将它们包含在我的原始答案中。

  1. 可扩展性。如果要计算其他列，则很难一遍又一遍地重写相同的行。相反，我建议您将总和存储在对象中。

  2. 值获取。我们正在根据列中的文本节点检索值。有时，您不希望这样 - 假设您想在数量和/或价格列中包含货币或其他文本。从这个意义上说，您可能希望将此类数据存储在自定义 HTML5data-属性中。

$(function() {
// Function to compute sum
var computeSum = function() {
// Get the total quantity and price by column index
var sums = { quantity: 0, price: 0 };
// Iterate through each table cell
$('#TableBody tr').each(function() {
sums.quantity += +$(this).find('td').eq(4).data('value');
sums.price += (+$(this).find('td').eq(4).data('value')*+$(this).find('td').eq(5).data('value'));
});
// Update sum
$.each(sums, function(key, value) {
$('#TableFooter td.total.'+key).text(value.toFixed(2));
});
};
// Use on to bind click event handlers to input buttons with delete-row action
$('#Table').on('click', 'input[type="button"][data-action="delete-row"]', function(e) {
e.preventDefault();
// Delete row
$(this).closest('tr').remove();
// Recompute sum
computeSum();
});
$('#xd').click(function() {
// Remember to wrap your cells within <tr>
var lines = "<tr>";
lines += '<td>3</td>';
lines += '<td>3</td>';
lines += '<td>15</td>';
lines += '<td>Credit</td>';
lines += '<td class="quantity" data-value="1">1</td>';
lines += '<td class="price" data-value="100.00">100.00</td>';
lines += '<td><input type="button" value="Delete" data-action="delete-row" /></td>';
lines += "</tr>";
// Append new table row
$('#TableBody').append(lines);
// Recompute sum
computeSum();
});
// Compute sum when starting up
computeSum();
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<table id="Table">
<thead>
<tr>
<td>ID</td>
<td>Code</td>
<td>Client</td>
<td>Debit/Credit</td>
<td>Quantity</td>
<td>Price</td>
<td>Options</td>
</tr>
</thead>
<tbody id="TableBody">
<tr>
<td>1</td>
<td>1</td>
<td>3</td>
<td>Debit</td>
<td class="quantity" data-value="10">10</td>
<td class="price" data-value="12.00">12.00</td>
<td>
<input type="button" value="Delete" data-action="delete-row" />
</td>
</tr>
<tr>
<td>2</td>
<td>2</td>
<td>12</td>
<td>Debit</td>
<td class="quantity" data-value="5">5</td>
<td class="price" data-value="10.00">10.00</td>
<td>
<input type="button" value="Delete" data-action="delete-row" />
</td>
</tr>
</tbody>
<tfoot id="TableFooter">
<tr>
<td colspan="4">Total</td>
<td class="total quantity">15</td>
<td class="total price">170.00</td>
</tr>
</tfoot>
</table>
<input type="button" id="xd" value="add row">

相关内容

最新更新


热门标签：

javascript python java c# php android html jquery c++ css ios sql mysql arrays asp.net json python-3.x ruby-on-rails .net sql-server django objective-c excel regex ruby linux ajax iphone xml vba spring asp.net-mvc database wordpress string postgresql wpf windows xcode bash git oracle list vb.net multithreading eclipse algorithm macos powershell visual-studio image forms numpy scala function api selenium