JSP JSTL < c: forEach > Tag

Have you ever used JSTL <c:forEach> to iterate a Collection such as List or Array in JSP page? It's a basic iteration tag, accepting many different collection types and supporting subsetting and other functionality.

Step 1: Attribute list of <c:forEach>

The tag has following attributes:

Attribute	Description	Required	Default
items	Collection of items to iterate over.	No	None
begin	Iteration begins at the item located at the specified index	No	0
end	Iteration ends at the item located at the specified index (inclusive). If items not specified: Iteration ends when index reaches the value specified.	No	Last element
step	teration will only process every step items of the collection, starting with the first one.	No	1
var	Name of the exported scoped variable for the current item of the iteration. This scoped variable has nested visibility. Its type depends on the object of the underlying collection.	No	None
varStatus	Name of the exported scoped variable for the status of the iteration. Object exported is of type javax.servlet.jsp.jstl.core.LoopTagStatus. This scoped variable has nested visibility.	No	None

Step 2: Try basic loop example :

 <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html>
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
   <title>Basic <c:forEach> loop example </title>
   <c:forEach var="item" begin="1" end="6">
      <p>Item ${item}</p> 
   </c:forEach>
</body>
</html>

Remember to include tag lib : http://java.sun.com/jsp/jstl/core to make this tag can execute. In will see the result of above example like followings:

Step 2: <c:forEach> Step Attribute

Change our basic example a little bit. In <c:forEach>, just add attribute step="2", and reload your page

 <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html>
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
   <title>Basic <c:forEach> loop example </title>
   <c:forEach var="item" begin="1" end="6" step="2">
      <p>Item ${item}</p> 
   </c:forEach>
</body>
</html>

As you can see, the just loop Item 1,3,5 from 1 to 6.

Step 3: Iterate a Collaction (list,Array...) by using attribute: " items"

In a lot of web application, we have to print out a list of Array which is sent from Java servlet. We can use <c:for Each> to loop over all elements of list and generate HTML code to sent to display in Client.

To do in this Example, I create a ArrayList <String> in Servlet like following statements:

        List codingTipList = new ArrayList();
        codingTipList.add("Java");
        codingTipList.add("Python");
        codingTipList.add("PHP");
        codingTipList.add("HTML");
        codingTipList.add("CSS");
        codingTipList.add("Javascript");
        
        requestScope("codingTipList",codingTipList);

now, I have an Array List with six Elements. In JSP page normally I have the <c:forEach> loop:

<c:forEach var="item" items="${codingTipList}">
   <p>Item ${item}</p>
</c:forEach>

you can add begin and end attribute, too.

<c:forEach var="item" begin="1" end="6" items="${codingTipList}" >   <p>Item ${item}</p>
</c:forEach>

Also, do the same with step

<c:forEach var="item" begin="1" end="6" step="2" items="${codingTipList}">   <p>Item ${item}</p>
</c:forEach>

and now, let's try varStatus, it's a bit different.

Step 4: <c:forEach> Show index of current Item of Collection

As I mentioned above, We have an attribute called "varStatus". It's an object save the loop Status. So, if you want to print out the index of Element when looping a list or Array, just called out index attribute of varStatus Object like following:

<c:forEach var="item" begin="1" end="6" step="2" varStatus="loopStatus" items="${codingTipList}">
   <p>Item ${item}: ${loopStatus.index}</p>
</c:forEach>

Result: