Use of Tag of JSTL

In this section, you will learn how to use Tag of JSTL.

Use of Tag of JSTL

Use of <fn:indexOf(String, String)> Tag of JSTL

     

In this section we will learn how to use <fn:indexOf> Tag of JSTL. This tag returns index of first occurrence of specified sub string in the given string string. This takes string type as arguments and returns int type.

 

Syntax :
int indexOf(java.lang.String, java.lang.String)








indexOf_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:indexof tag of JSTL</title>
    </head>
    <body>
        <form method="POST">
            This will calculate the first occurance of given 
            character/string in the <br>specified String.
            <table>
                <tr>
                    <td>Enter Text</td>
                    <td><input type="text" name="text"></td>
                </tr>
                
                <tr>
                    <td>Search</td>
                    <td><input type="text" name="str"></td>
                </tr>
                
                <tr>
                    <td></td>
                    <td><input type="submit" value="search"></td>
                </tr>
            </table>  
        </form>
        <c:if test="${pageContext.request.method=='POST'}">
            <c:set var="text" value="${param.text}"/>
            <c:set var="str" value="${param.str}"/>
            
            <font size="5" color="#1B2A0A">
                Index of first occurance : 
            </font>
            <font size="5" color="green">

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

 

This jsp code shows the following output :

 

Suppose in 'mahendra singh' string user want to find index of the first occurrence of 'e'....




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




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