Javascript:计算每个表的表行数,并向相应的元素返回一个值
我在一个网页上有三个表格。每个表都有一个嵌套在Javascript:计算每个表的表行数,并向相应的元素返回一个值,javascript,html,html-table,Javascript,Html,Html Table,我在一个网页上有三个表格。每个表都有一个嵌套在标记中的对应元素,我需要反映其各自表中的行数,减去首行和底行(-2)。当我使用单个表时,此代码工作正常: HTML表格片段: <table class="table" id="category"> <thead> <tr> <th><i class="fa fa-hashtag"></i> headache - <
标记中的对应元素,我需要反映其各自表中的行数,减去首行和底行(-2)。当我使用单个表时,此代码工作正常:
HTML表格片段:
<table class="table" id="category">
<thead>
<tr>
<th><i class="fa fa-hashtag"></i> headache - <label class="label label-primary" id="tableBadge">0</span></th>
<th><i class="fa fa-calendar"></i> Date Added</th>
<th><i class="fa fa-cog"></i> Options</th>
</tr>
</thead>
<tbody>
<tr>
<td>Test entry</td>
<td>1/19/2016</td>
<td>
<a href="#" class="btn btn-success btn-xs"><i class="fa fa-pencil"></i></a>
<a href="#" class="btn btn-primary btn-xs"><i class="fa fa-calendar"></i></a>
<a href="#" class="btn btn-danger btn-xs"><i class="fa fa-trash"></i></a>
</td>
</tr>
<tr>
<td><a href="#" class="btn btn-default btn-xs"><i class="fa fa-plus"></i> add entry</a></td>
</td>
</tr>
</tbody>
</table>
然而,考虑到HTML的规则,ID对于元素来说是唯一的,我处于一个绑定中。使用getElementsByClassName()
或getElementsByTagName()
值返回0,告诉我它不工作。至少使用相同的语法
我在Google等网站上搜索了一个解决方案,但它们似乎是针对行的总量而定制的,而不是针对各自表的单个计数
任何帮助都将不胜感激。提前感谢。尝试使用
查询选择器all
如下:
document.querySelectorAll('.table>thead>tr')
数组的长度可能是您要查找的答案将id tableBadge更改为tableBadge_类别,类似于其他表格 “table_id”是table的id,您跨越的是tableBadge_table_id
getElementsByTagName和getElementsByClassNAme返回节点列表,您需要对它们进行迭代
window.addEventListener('load', function(e) {
//This is a node list you must iterate
var tables = document.getElementsByTagName('table');
for (var i = 0; i < tables.length; i++) {
//This loop will handle each tble selected
var table = tables[i];
var totalRows = table.rows.length;
console.log(totalRows);
//Add your code here
}
}, false);
window.addEventListener('load',函数(e){
//这是一个必须迭代的节点列表
var tables=document.getElementsByTagName('table');
对于(变量i=0;i
虽然您已经接受了答案,但我建议下面的内容可能会稍微有用一点,而且对硬编码豁免的依赖性也会大大降低(因此对未来的维护噩梦也会减少)
也就是说,我的解决方案是将“页脚”放在
元素中,以便相关的
元素都包含在
的
元素中
我建议使用JavaScript函数:
// wrapping the function in an Immediately-Invoked Function Expression
// ("IIFE") in order that it runs immediately and does not require
// calling later:
(function() {
// using 'let' (rather than var) to declare local variables, all
// of which are available only within the block in which they're
// declared; here we convert the NodeList returned by
// document.querySelectorAll('span.label') into an Array, using
// Array.from():
let outputs = Array.from(document.querySelectorAll('span.label')),
// declaring another variable for later use:
tbodies;
// iterating over each of the found 'span.label' elements
// in the Array, using Array.prototype.forEach():
outputs.forEach(function(span) {
// the first argument (here 'span') is the current
// array-element of the array over which we're iterating.
// finding the closest ancestor <table> element from the
// current span node, and then finding all the <tbody>
// elements contained within that <table>, and converting
// that NodeList to an Array, again using Array.from() to
// do so:
tbodies = Array.from(span.closest('table').querySelectorAll('tbody'));
// updating the text-content of the span to:
// the sum of the child <tr> elements found in each of
// the <tbody> elements found within the <table>, using
// Array.prototype.reduce() to reduce the Array to a single
// (here numeric) value; here we use an Arrow Function
// to add the number of children of the <tbody> element
// to the initialValue of the reduce method (0, the
// final argument following the comma):
span.textContent = tbodies.reduce((initialValue, tbody) => a + tbody.children.length, 0);
});
// here the function is invoked:
})();
头痛-
添加日期
选择权
测试条目
1/19/2016
能否显示您正在使用的完整的
?根据请求进行更新。计数是否动态变化,以及响应什么?还是在页面的整个“生命周期”内保持不变?其思想是,当创建新条目时,页面重新加载时计数将增加。我不太关心“实时更新”。在表中显示的“计数”(可能在元素#tablebadge
中)应该是0,还是应该是1?实际上,我在问哪些行应该从计数中扣除,哪些应该被计数?你认为“标题”和“页脚”是哪一个?既然您使用的是thead
和tbody
,为什么不同时使用tfoot
来清楚地包含您不想计数的行呢?这样做很好。非常感谢你!我建议稍作修改—不要获取table元素本身的行.length
,而是获取tbody元素的document.getElementById(table_id).tBodies[0].rows.length
,并放入“底层行”(这似乎有特殊含义,不能被视为正常的“条目”由于前面的行是)到tfoot
元素中的,因此您不必减去“幻数”2,这意味着如果将另一个表行添加到thead中,您不必调整代码。这正是我所做的。非常感谢您的输入和Cuchu对我的帮助。行计数选项:var rowCount=$(“#myTable tr”).length;
window.addEventListener('load', function(e) {
//This is a node list you must iterate
var tables = document.getElementsByTagName('table');
for (var i = 0; i < tables.length; i++) {
//This loop will handle each tble selected
var table = tables[i];
var totalRows = table.rows.length;
console.log(totalRows);
//Add your code here
}
}, false);
// wrapping the function in an Immediately-Invoked Function Expression
// ("IIFE") in order that it runs immediately and does not require
// calling later:
(function() {
// using 'let' (rather than var) to declare local variables, all
// of which are available only within the block in which they're
// declared; here we convert the NodeList returned by
// document.querySelectorAll('span.label') into an Array, using
// Array.from():
let outputs = Array.from(document.querySelectorAll('span.label')),
// declaring another variable for later use:
tbodies;
// iterating over each of the found 'span.label' elements
// in the Array, using Array.prototype.forEach():
outputs.forEach(function(span) {
// the first argument (here 'span') is the current
// array-element of the array over which we're iterating.
// finding the closest ancestor <table> element from the
// current span node, and then finding all the <tbody>
// elements contained within that <table>, and converting
// that NodeList to an Array, again using Array.from() to
// do so:
tbodies = Array.from(span.closest('table').querySelectorAll('tbody'));
// updating the text-content of the span to:
// the sum of the child <tr> elements found in each of
// the <tbody> elements found within the <table>, using
// Array.prototype.reduce() to reduce the Array to a single
// (here numeric) value; here we use an Arrow Function
// to add the number of children of the <tbody> element
// to the initialValue of the reduce method (0, the
// final argument following the comma):
span.textContent = tbodies.reduce((initialValue, tbody) => a + tbody.children.length, 0);
});
// here the function is invoked:
})();