问题描述
我正在处理从API中获取信息，并希望将这些数据插入到 for-loop 中的不同类的某些元素中。现在我通过包装在 .each（）方法中的 switch-statement 来做这件事。看起来这种方式是重复的，可能比任何事情都重要。有没有办法以更简洁高效的方式来实现这一点？
您可以编码：
$（'tbody td span'）。text（function（）{
var i = this.parentNode.parentNode.rowIndex - 1;
return tracks [i] [this.className];
}）;
在上面的代码片段 rowIndex code> tr 元素用于通过索引获取特定数组的元素。使用括号表示法（ [index] ）和 span 的 className $ c>元素，相应的属性值由 text 方法设置。
由于表格有第一个 tr thead 元素中的第一行 rowIndex tbody 元素的子元素是 1 。这就是为什么返回的值减1。
注意，您应该考虑根据 tr 元素生成元素到返回的数据。使用模板库可以是一个选项。
编辑：您也可以使用vanilla JavaScript：
var spans = document.querySelectorAll（'tbody td span'）;
Array.prototype.forEach.call（spans，function（el）{
var i = el.parentNode.parentNode.rowIndex - 1;
el.textContent = tracks [i] [el .className];
}）;
I'm dealing with pulling in information from an API and want to take that data and inserting it into certain elements of different classes within a for-loop. Right now I'm doing this through a switch-statement wrapped inside an .each() method. It just seems that this way for one is repetitive and probably is more performance heavy than anything. Is there a way to accomplish this in a more concise and efficient way?
var tracks = [{number: "01", title: "Track 1", duration: "5:35"}, {number: "02", title: "Track 2", duration: "5:15"}, {number: "03", title: "Track 3", duration: "5:07"}, {number: "04", title: "Track 4", duration: "0:16"}, {number: "05", title: "Track 5", duration: "5:35"}];
for (var i = 0, trackNumber, trackTitle, trackDuration; i < tracks.length; i++) {
trackNumber = tracks[i]["number"];
trackTitle = tracks[i]["title"];
trackDuration = tracks[i]["duration"];
$("span").each(function() {
switch($(this).attr("class")) {
case "number":
$(".number").eq(i).text(trackNumber);
case "title":
$(".title").eq(i).text(trackTitle);
case "duration":
$(".duration").eq(i).text(trackDuration);
default:
//
}
});
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<table>
<thead>
<tr>
<td><b>No</b></td>
<td><b>Title</b></td>
<td><b>Duration</b></td>
</tr>
</thead>
<tr>
<td><span class="number"></span></td>
<td><span class="title"></span></td>
<td><span class="duration"></span></td>
</tr>
<tr>
<td><span class="number"></span></td>
<td><span class="title"></span></td>
<td><span class="duration"></span></td>
</tr>
<tr>
<td><span class="number"></span></td>
<td><span class="title"></span></td>
<td><span class="duration"></span></td>
</tr>
<tr>
<td><span class="number"></span></td>
<td><span class="title"></span></td>
<td><span class="duration"></span></td>
</tr>
<tr>
<td><span class="number"></span></td>
<td><span class="title"></span></td>
<td><span class="duration"></span></td>
</tr>
</table>You could code:
$('tbody td span').text(function() {
var i = this.parentNode.parentNode.rowIndex - 1;
return tracks[i][this.className];
});
In the above snippet rowIndex of the tr elements is used for getting a specific array's element by index. Using bracket notation ([index]) and the className of the span element the corresponding property's value is set by the text method. Here is a demo.
As the table has one 1 row in the thead element the rowIndex of the first tr child of the tbody element is 1. That's why the returned value is subtracted by 1.
As a note, you should consider generating the tr elements according to the returned data. Using a templating library can be an option.
edit: You could also use vanilla JavaScript:
var spans = document.querySelectorAll('tbody td span');
Array.prototype.forEach.call(spans, function (el) {
var i = el.parentNode.parentNode.rowIndex - 1;
el.textContent = tracks[i][el.className];
});
这篇关于for循环中的元素的质量分配的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！