JSTL foreach loop inwards JSP
JSTL foreach tag is pretty useful spell writing Java complimentary JSP code. JSTL foreach tag allows you lot to iterate or loop Array List, HashSet or whatever other collection without using Java code. After introduction of JSTL together with appear 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 together with behaves similarly similar foreach loop of Java v but nevertheless has closed to elements together with attribute which makes it difficult for first-timers to grasp it. JSTL foreach loop tin post away iterate over arrays, collections similar List, Set together with 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 empathize together with utilisation foreach loop inwards JSP. By the agency this is our instant JSP tutorial on JSTL center library, inwards final tutorial nosotros convey seen How to utilisation center <c:set> tag inwards JSP page.
How to utilisation forEach tag inwards JSP page
forEach tag is business office of criterion JSTL center bundle together with written as <foreach> or <c:foreach> or <core:foreach> whatever prefix you lot are using inwards taglib directive spell importing JSTL center library. In social club to utilisation foreach tag inwards JSP pages you lot ask to import JSTL tag library inwards jsp together with every bit good ask to include jstl.jar inwards your WEB-INF/lib directory or inwards Java classpath. if you lot are using Eclipse or Netbeans IDE than it volition deal you lot on on code completion of foreach tag otherwise you lot ask to scream upward its basic syntax every bit shown below: Syntax of foreach tag inwards JSTL
<c:forEach var="name of scoped variable"
items="Colleciton,List or Array" varStatus="status">
where var together with items are manadatory together with 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 closed to to a greater extent than examples of using foreach tag inwards JSP page for looping purpose. Just campaign distich of instance together with you lot 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 you lot ask to create those collections together with shop that into whatever compass mentioned to a higher house e.g. pageScope together with than access it using appear linguistic communication similar ${pageScope.myList}. run into the JSP page inwards final instance for consummate code instance of foreach tag.
Iterating over array using JSTL forEach loop
For iterating over an array e.g. String array or integer array inwards JSP page, "items" attribute must resolved to an array. You tin post away utilisation appear linguistic communication to larn an Array stored inwards of compass available inwards JSP e.g. page scope, asking scope, session or application scope. These are dissimilar than bean compass inwards Spring MVC together with don’t confuse betwixt Spring edible bean compass together with JSP variable compass if you lot are using Spring MVC inwards your Java spider web application. Rest of foreach loop volition live similar to foreach loop instance of iterating over Collections inwards Java.
JSTL foreach instance using varStatus variable
varStatus attribute declare scream of variable which holds electrical current looping counter for foreach tag. It every bit good divulge several useful information which you lot tin post away access using varStatus e.g. what is electrical current row, whether you lot are inwards final row etc. Here is a code instance of how to utilisation varStatus inwards foreach JSTL tag on JSP:
<%-- JSTL foreach tag varStatus instance to exhibit count inwards JSP --%>
<c:forEach var="window" items="${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 inwards JSP
count: 1 Windows XP
count: 2 Windows 7
count: iii Windows 8
count: iv Windows mobile
</c:forEach>
Output:
JSTL foreach tag instance inwards 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 together with count
Nested foreach tag instance inwards JSP JSTL
Another skilful affair of JSTL foreach tag is you lot tin post away nest foreach tag loop within closed to other foreach tag which is quite powerful agency of looping without using scriptlets inwards JSP. Here is an instance of nesting foreach tag inwards JSP JSTL tag library:
<%-- JSTL foreach tag instance to loop an array inwards JSP together with 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: ${loopCounter.count}"/>
</c:forEach>
</c:forEach>
Output:
outer loop count: 1
inner loop count: 1
inner loop count: 2
outer loop count: 2
inner loop count: 1
inner loop count: 2
Complete JSTL foreach loop instance inwards JSP
Here is consummate JSP page which shows how to utilisation JSTL foreach tag for looping over String array . Similarly you lot tin post away loop over whatever Collection e.g. List or Set every bit well.
<%@page import="java.util.List"%>
<%@page import="java.util.Arrays"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Welcome to JSTL foreach tag Example inwards JSP</title>
</head>
<body>
<h2>JSTL foreach tag instance inwards JSP</h2>
<jsp:scriptlet>
String[] windows = novel String[]{"Windows XP", "Windows 7", "Windows 8", "Windows mobile"};
pageContext.setAttribute("windows", windows);
</jsp:scriptlet>
<%-- JSTL foreach tag instance to loop an array inwards jsp --%>
<c:forEach var="window" items="${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 inwards JSP</title>
</head>
<body>
<h2>JSTL foreach tag instance inwards 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 inwards jsp --%>
<c:forEach var="window" items="${pageScope.windows}">
<c:out value="${window}"/>
</c:forEach>
</body>
</html>
Output:
JSTL foreach tag instance inwards JSP
Windows XP
Windows 7
Windows 8
Windows mobile
</body>
</html>
Output:
JSTL foreach tag instance inwards JSP
Windows XP
Windows 7
Windows 8
Windows mobile
That’s all on How to utilisation JSTL forEach loop instance inwards JSP page. We convey seen JSTL foreach tag instance of Iterating or looping over Array, List, Collection together with nesting of ii forEach loop which allows you lot to write powerful JSP pages without using whatever Java code.
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