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JSTL Core c:if Tag

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The <c:if> tag is the most useful of tags of JSTL core tag library. This tag evaluates an expression and displays its body content only if the expression is true. This tag allows test for condition, condition like checking for particular parameters in requestScope, sessionScope or pageScope.

Syntax For c:if Tag

<c:if attribute> body content </c:if>

Attribute In c:if Tag

  • test: This condition determines whether or not the body content should be processed.
  • var: Name of the exported scoped variable for the resulting value of the test condition. The type of the scoped variable is Boolean.
  • scope: Scope of the variable to store the condition’s result.

Example of c:if Tag

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"

   pageEncoding="ISO-8859-1"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<span style="font-size: 12px; line-height: 18px;"><html></span>
<span style="font-size: 12px; line-height: 18px;"><head></span>
<span style="font-size: 12px; line-height: 18px;"><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"></span>
<span style="font-size: 12px; line-height: 18px;"><title>JSTL If Tag Example</title></span>
<span style="font-size: 12px; line-height: 18px;"></head></span>
<span style="font-size: 12px; line-height: 18px;"><body></span>
<span style="font-size: 12px; line-height: 18px;">  <c:set var="weight" value="92"></span>
<span style="font-size: 12px; line-height: 18px;">  </c:set></span>
<span style="font-size: 12px; line-height: 18px;"> <c:if test="${weight != null}"></span>
<span style="font-size: 12px; line-height: 18px;"> Weight of the product is ${weight * 0.453592} kgs. </span>
<span style="font-size: 12px; line-height: 18px;"> </c:if> </span>
<span style="font-size: 12px; line-height: 18px;"></body></span>
</html>

How To Run?

  • Save this file as example.jsp in your eclipse IDE.
  • Now select this jsp file, right mouse click and select Run as ->Run on server

Output

When the execution process is completed successfully we will get the following output :
jstl_core c if tag_demo

Previous Tutorial : JSTL Core c:catch Tag :: Next Tutorial : JSTL Core c:choose,  c:when, c:otherwise Tags

About Krishna Srinivasan

He is Founder and Chief Editor of JavaBeat. He has more than 8+ years of experience on developing Web applications. He writes about Spring, DOJO, JSF, Hibernate and many other emerging technologies in this blog.