Java 如何从jstl的foreach循环中获取索引值
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How to get a index value from foreach loop in jstl
提问by Java Questions
I have a value set in the requestobject like the following,
我在request对象中设置了一个值，如下所示，
String[] categoriesList=null;
categoriesList = engine.getCategoryNamesArray();
request.setAttribute("categoriesList", categoriesList );
and this is how I iterate in jsp page
这就是我在jsp页面中迭代的方式
<% if(request.getAttribute("categoriesList") != null) { %>
<c:forEach var="categoryName" items="${categoriesList}">
<li><a onclick="getCategoryIndex()" href="#">${categoryName}</a></li>
</c:forEach>
<% }%>
How do I get index of each element and pass it to JavaScript function onclick="getCategoryIndex()".
如何获取每个元素的索引并将其传递给 JavaScript 函数onclick="getCategoryIndex()"。
采纳答案by newuser
use varStatusto get the index c:forEach varStatus properties
使用varStatus获取索引 c:forEach varStatus 属性
<c:forEach var="categoryName" items="${categoriesList}" varStatus="loop">
<li><a onclick="getCategoryIndex(${loop.index})" href="#">${categoryName}</a></li>
</c:forEach>
回答by SudoRahul
You can use the varStatusattribute like this:-
您可以varStatus像这样使用属性：-
<c:forEach var="categoryName" items="${categoriesList}" varStatus="myIndex">
myIndex.indexwill give you the index. Here myIndexis a LoopTagStatusobject.
myIndex.index会给你索引。这myIndex是一个LoopTagStatus对象。
Hence, you can send that to your javascript method like this:-
因此，您可以像这样将其发送到您的 javascript 方法：-
<a onclick="getCategoryIndex(${myIndex.index})" href="#">${categoryName}</a>
回答by Laxman G
I face Similar problem now I understand we have some more option : varStatus="loop", Here will be loop will variable which will hold the index of lop.
我面临类似的问题，现在我知道我们有更多的选择：varStatus="loop"，这里将是循环变量，它将保存 lop 的索引。
It can use for use to read for Zeor base index or 1 one base index.
它可以用于读取零基索引或 1 一基索引。
${loop.count}` it will give 1 starting base index.
${loop.index} it will give 0 base index as normal Index of arraystart from 0.
${loop.index} it will give 0 base index as normal Index of array从0开始。
For Example :
例如 ：
<c:forEach var="currentImage" items="${cityBannerImages}" varStatus="loop">
<picture>
<source srcset="${currentImage}" media="(min-width: 1000px)"></source>
<source srcset="${cityMobileImages[loop.count]}" media="(min-width:600px)"></source>
<img srcset="${cityMobileImages[loop.count]}" alt=""></img>
</picture>
</c:forEach>
For more Info please refer this link
有关更多信息，请参阅此链接
回答by Rakesh Kumar
<a onclick="getCategoryIndex(${myIndex.index})" href="#">${categoryName}</a>
above line was giving me an error. So I wrote down in below way which is working fine for me.
上面那行给了我一个错误。所以我用下面的方式写下了这对我来说很好。
<a onclick="getCategoryIndex('<c:out value="${myIndex.index}"/>')" href="#">${categoryName}</a>
Maybe someone else might get same error. Look at this guys!
也许其他人可能会遇到同样的错误。看看这些家伙！
回答by Pradeep
This works for me:
这对我有用：
<c:forEach var="i" begin="1970" end="2000">
<option value="${2000-(i-1970)}">${2000-(i-1970)}
</option>
</c:forEach>
