JSP/Servlet | JSTL(JSP Standard Tag Library) | Loops <c:forEach>, <c:forTokens>

Tags:

Loops are used to repeat the same task a specific number of times. In JSTL, let’s look at the most commonly used loop, <c:forEach>.

Directive declaration

To use loops, you need the JSTL core declaration at the top of the JSP page.

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

Loop using a <c:forEach> list

<c:forEach> receives a list and repeats as many times as the number of items in the list.

Attribute descriptions

Item Description Required Default
var Variable name to use Required None
items Collection object, such as List or Map Required
begin Loop start index. If undefined, 0 0
end Loop end index Last index
step Number of indexes to skip each time it repeats
varStatus Variable that provides loop status

varStatus value descriptions

Value Return Description
index int Index number pointing to the item defined in items. Starts from 0.
count int Indicates the current iteration number. Starts from 1.
first boolean Whether the current iteration is the first
last boolean Whether the current iteration is the last

Usage examples

Example using all attributes

<c:forEach var="item" items="${items}" begin="0" end="10" step="1" varStatus="status">
    <p>No.: ${status.index}</p>
    <p>Book title: ${item.name}</p>
    <p>Author: ${item.author}</p>
    <p>Publisher: ${item.publisher}</p>
</c:forEach>

This example repeats from 0 to 10 for ${items} and displays the list.

Common usage example

<c:forEach var="item" items="${items}">
    <p>No.: ${status.index}</p>
    <p>Book title: ${item.name}</p>
    <p>Author: ${item.author}</p>
    <p>Publisher: ${item.publisher}</p>
</c:forEach>

Loop using <c:forTokens> tokens

This loop splits a string by a specific delimiter and repeats over the results. It works similarly to StringTokenizer in Java.

Attribute descriptions

Item Description Required Default
delims Specific delimiter used to split the string Required

Usage example

<ol>
<c:forTokens var="item" items="apple,grape,banana,watermelon,strawberry" delims=",">
    <li>Fruit: ${item}</li>
</c:forTokens>
</ol>

Put the string in items and the delimiter in delims. Each string separated by token can be obtained through the variable specified by var.