javascript 获取 jquery 中的最后一次迭代
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get the last iteration in jquery each
提问by Asim Zaidi
I have the following code that I am going through the tables columns and if its the last column I want it to do something different. Right now its hard coded but how can I change so it automatically knows its the last column
我有以下代码，我正在浏览表格列，如果它是最后一列，我希望它做一些不同的事情。现在它是硬编码的，但我该如何更改以便它自动知道它的最后一列
$(this).find('td').each(function (i) {
if(i > 0) //this one is fine..first column
{
if(i < 4) // hard coded..I want this to change
{
storageVAR += $(this).find('.'+classTD).val()+',';
}
else
{
storageVAR += $(this).find('.'+classTD).val();
}
}
});
回答by jfriend00
If you want access to the length inside the .each()callback, then you just need to get the length beforehand so it's available in your scope.
如果您想访问.each()回调中的长度，那么您只需要事先获取长度，以便它在您的范围内可用。
var cells = $(this).find('td');
var length = cells.length;
cells.each(function(i) {
// you can refer to length now
});
回答by loganfsmyth
It looks like your objective is to make a comma separated list of the values, why don't you collect the values and use the array method 'join'?
看起来您的目标是制作一个逗号分隔的值列表，为什么不收集值并使用数组方法“join”？
var values = []
$(this).find('td .' + classTD).each(function(i) {
if (i > 0) values.push($(this).val());
});
storageVAR = values.join(',');
回答by Bj?rn Thomsen
Something like this should do it:
像这样的事情应该这样做：
var $this = $(this),
size = $this.length,
last_index = size -1;
$this.find('td').each(function (index) {
if(index == 0) {
// FIRST
} else if(index === last_index) {
// LAST
} else {
// ALL THE OTHERS
}
});
回答by Grim...
If all you want is the last column, you can use
如果你想要的只是最后一列，你可以使用
$(this).find('td:last')
If you want to do things with other columns, go for
如果你想用其他列做事，去
$(this).find('td:last').addClass("last");
$(this).find('td').each(function() {
if ($(this).hasClass("last")) {
// this is the last column
} else {
// this isn't the last column
}
});
You can use data()instead of addclass()if you're comfortable with that.
如果您对此感到满意data()，addclass()则可以使用代替。
If all you want to do is not have a comma at the end of your string, you could just chop it off afterward:
如果您只想在字符串末尾没有逗号，则可以在之后将其砍掉：
storageVAR = storageVAR.substr(0, (storageVAR.length - 1);
