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Use of <fn:length(String)> Tag of JSTL

In this section we will learn how to use <fn:length> Tag of JSTL. This tag returns the number of items in a collection, or the number of characters in a string. This takes Object type as arguments and returns int type.

Syntax :

int length(java.lang.Object)

length_fnJstlTag.jsp

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

<html>
    <head>
        <title>Example of fn:length tag of JSTL</title>
    </head>
    <body>
        <form method="POST">
            This will calculate the length of specified string.
            <table>
                <tr>
                    <td>Enter String</td>
                    <td><input type="text" name="text"></td>
                </tr>

                <tr>
                    <td></td>
                    <td><input type="submit" value="calculate"></td>
                </tr>
            </table>  
        </form>
        <c:if test="${pageContext.request.method=='POST'}">
            <c:set var="text" value="${param.text}"/>

            <font size="5" color="#1B2A0A">
                Length : 
            </font>
            <font size="5" color="green">

                <c:out value="${fn:length(text)}"/>
                
            </font>
        </c:if>
    </body>
</html>

This jsp code shows the following output :

Suppose in user wants to calculate the length of string 'mahendra singh'.....

When user clicks on calculate button, output will be.....

Download Source Code

Use of Tag of JSTL

Use of Tag of JSTL

Use of <fn:length(String)> Tag of JSTL

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