Jstl Foreach Tag Illustration Inward Jsp - Looping Arraylist
JSTL foreach loop inward JSP
JSTL foreach tag is pretty useful land writing Java gratis JSP code. JSTL foreach tag allows yous to iterate or loop Array List, HashSet or whatever other collection without using Java code. After introduction of JSTL in addition to aspect language(EL) it is possible to write dynamic JSP code without using scriptlet which clutters jsp pages. JSTL foreach tag is a replacement of for loop in addition to behaves similarly similar foreach loop of Java v but even in addition to hence has to a greater extent than or less elements in addition to attribute which makes it difficult for first-timers to grasp it. JSTL foreach loop tin iterate over arrays, collections similar List, Set in addition to impress values simply similar for loop. In this JSP tutorial nosotros volition run into distich of instance of foreach loop which makes it tardily for novel guys to sympathise in addition to job foreach loop inward JSP. By the agency this is our minute JSP tutorial on JSTL center library, inward concluding tutorial nosotros convey seen How to job center <c:set> tag inward JSP page.
How to job forEach tag inward JSP page
forEach tag is business office of measure JSTL center packet in addition to written as <foreach> or <c:foreach> or <core:foreach> whatever prefix yous are using inward taglib directive land importing JSTL center library. In social club to job foreach tag inward JSP pages yous necessitate to import JSTL tag library inward jsp in addition to likewise necessitate to include jstl.jar inward your WEB-INF/lib directory or inward Java classpath. if yous are using Eclipse or Netbeans IDE than it volition assist yous on on code completion of foreach tag otherwise yous necessitate to recollect its basic syntax equally shown below: Syntax of foreach tag inward JSTL
<c:forEach var="name of scoped variable"
items="Colleciton,List or Array" varStatus="status">
where var in addition to items are manadatory in addition to varStatus, begin, end or step attributes are optional. Here is an instance of foreach tag:
<c:forEach var="window" items="${pageScope.windows}">
<c:out value="${window}"/>
<c:out value="${window}"/>
</c:forEach>
above JSTL foreach tag is equivalent to next foreach loop of Java 1.5
foreach(String window: windows){
System.out.println(window);
}
System.out.println(window);
}
JSTL foreach tag examples
In this department of JSTL tutorial nosotros volition run into to a greater extent than or less to a greater extent than examples of using foreach tag inward JSP page for looping purpose. Just attempt distich of instance in addition to yous volition larn concur of foreach it looks to a greater extent than tardily afterwards trying few examples.
Iterating over collections or List using JSTL forEach loop
In social club to iterate over collections e.g. List or Set yous necessitate to create those collections in addition to shop that into whatever orbit mentioned inward a higher house e.g. pageScope in addition to than access it using aspect linguistic communication similar ${pageScope.myList}. run into the JSP page inward concluding instance for consummate code instance of foreach tag.
Iterating over array using JSTL forEach loop
For iterating over an array e.g. String array or integer array inward JSP page, "items" attribute must resolved to an array. You tin job aspect linguistic communication to larn an Array stored inward of orbit available inward JSP e.g. page scope, asking scope, session or application scope. These are dissimilar than bean orbit inward Spring MVC in addition to don’t confuse betwixt Spring edible bean orbit in addition to JSP variable orbit if yous are using Spring MVC inward your Java spider web application. Rest of foreach loop volition live similar to foreach loop instance of iterating over Collections inward Java.
JSTL foreach instance using varStatus variable
varStatus attribute declare shout of variable which holds electrical flow looping counter for foreach tag. It likewise give away several useful information which yous tin access using varStatus e.g. what is electrical flow row, whether yous are inward concluding row etc. Here is a code instance of how to job varStatus inward foreach JSTL tag on JSP:
<%-- JSTL foreach tag varStatus instance to present count inward JSP --%>
<c:forEach var="window" items="${pageScope.windows}" varStatus="loopCounter" >
<c:out value="count: ${loopCounter.count}"/>
<c:forEach var="window" items="${pageScope.windows}" varStatus="loopCounter" >
<c:out value="count: ${loopCounter.count}"/>
<c:out value="${window}"/>
</c:forEach>
Output:
JSTL foreach tag instance inward JSP
count: 1 Windows XP
count: 2 Windows 7
count: iii Windows 8
count: iv Windows mobile
</c:forEach>
Output:
JSTL foreach tag instance inward JSP
count: 1 Windows XP
count: 2 Windows 7
count: iii Windows 8
count: iv Windows mobile
Some other handy properties are : first, last, step, begin, end, current, index in addition to count
Nested foreach tag instance inward JSP JSTL
Another proficient affair of JSTL foreach tag is yous tin nest foreach tag loop within to a greater extent than or less other foreach tag which is quite powerful agency of looping without using scriptlets inward JSP. Here is an instance of nesting foreach tag inward JSP JSTL tag library:
<%-- JSTL foreach tag instance to loop an array inward JSP in addition to nesting of foreach loop --%>
<c:forEach var="window" items="${pageScope.windows}" varStatus="loopCounter" >
<c:out value="outer loop count: ${loopCounter.count}"/>
<c:forEach var="window" items="${pageScope.windows}" varStatus="loopCounter" >
<c:out value="outer loop count: ${loopCounter.count}"/>
<c:forEach var="window" items="${pageScope.windows}" varStatus="loopCounter" >
<c:out value="inner loop count: ${loopCounter.count}"/>
</c:forEach>
</c:forEach>
Output:
outer loop count: 1
inner loop count: 1
inner loop count: 2
outer loop count: 2
inner loop count: 1
inner loop count: 2
<c:out value="inner loop count: ${loopCounter.count}"/>
</c:forEach>
</c:forEach>
Output:
outer loop count: 1
inner loop count: 1
inner loop count: 2
outer loop count: 2
inner loop count: 1
inner loop count: 2
Complete JSTL foreach loop instance inward JSP
Here is consummate JSP page which shows how to job JSTL foreach tag for looping over String array . Similarly yous tin loop over whatever Collection e.g. List or Set equally well.
<%@page import="java.util.List"%>
<%@page import="java.util.Arrays"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Welcome to JSTL foreach tag Example inward JSP</title>
</head>
<body>
<h2>JSTL foreach tag instance inward JSP</h2>
<jsp:scriptlet>
String[] windows = novel String[]{"Windows XP", "Windows 7", "Windows 8", "Windows mobile"};
pageContext.setAttribute("windows", windows);
</jsp:scriptlet>
<%-- JSTL foreach tag instance to loop an array inward jsp --%>
<c:forEach var="window" items="${pageScope.windows}">
<%@page import="java.util.Arrays"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Welcome to JSTL foreach tag Example inward JSP</title>
</head>
<body>
<h2>JSTL foreach tag instance inward JSP</h2>
<jsp:scriptlet>
String[] windows = novel String[]{"Windows XP", "Windows 7", "Windows 8", "Windows mobile"};
pageContext.setAttribute("windows", windows);
</jsp:scriptlet>
<%-- JSTL foreach tag instance to loop an array inward jsp --%>
<c:forEach var="window" items="${pageScope.windows}">
<c:out value="${window}"/>
</c:forEach>
</body>
</html>
Output:
JSTL foreach tag instance inward JSP
Windows XP
Windows 7
Windows 8
Windows mobile
</body>
</html>
Output:
JSTL foreach tag instance inward JSP
Windows XP
Windows 7
Windows 8
Windows mobile
That’s all on How to job JSTL forEach loop instance inward JSP page. We convey seen JSTL foreach tag instance of Iterating or looping over Array, List, Collection in addition to nesting of 2 forEach loop which allows yous to write powerful JSP pages without using whatever Java code.
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