Jstl Foreach Tag Representative Inward Jsp - Looping Arraylist
Monday, July 9, 2018
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JSTL foreach loop inwards JSP
JSTL foreach tag is pretty useful field writing Java gratis JSP code. JSTL foreach tag allows you lot to iterate or loop Array List, HashSet or whatsoever other collection without using Java code. After introduction of JSTL together with 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 together with behaves similarly similar foreach loop of Java five but however has about elements together with attribute which makes it difficult for first-timers to grasp it. JSTL foreach loop tin iterate over arrays, collections similar List, Set together with impress values merely similar for loop. In this JSP tutorial nosotros volition encounter span of event of foreach loop which makes it slowly for novel guys to empathize together with exercise foreach loop inwards JSP. By the agency this is our minute JSP tutorial on JSTL meat library, inwards final tutorial nosotros convey seen How to exercise meat <c:set> tag inwards JSP page.
How to exercise forEach tag inwards JSP page
forEach tag is business office of touchstone JSTL meat parcel together with written as <foreach> or <c:foreach> or <core:foreach> whatever prefix you lot are using inwards taglib directive field importing JSTL meat library. In lodge to exercise foreach tag inwards JSP pages you lot postulate to import JSTL tag library inwards jsp together with likewise postulate 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 assist you lot on on code completion of foreach tag otherwise you lot postulate to retrieve its basic syntax equally 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 event 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 encounter about to a greater extent than examples of using foreach tag inwards JSP page for looping purpose. Just endeavor span of event together with you lot volition larn concur of foreach it looks to a greater extent than slowly afterwards trying few examples.
Iterating over collections or List using JSTL forEach loop
In lodge to iterate over collections e.g. List or Set you lot postulate to create those collections together with shop that into whatsoever reach mentioned higher upward e.g. pageScope together with than access it using aspect linguistic communication similar ${pageScope.myList}. encounter the JSP page inwards final event for consummate code event of foreach tag.
Iterating over array using JSTL forEach loop
For iterating over an array e.g. String array or integer array inwards JSP page, "items" attribute must resolved to an array. You tin exercise aspect linguistic communication to larn an Array stored inwards of reach available inwards JSP e.g. page scope, asking scope, session or application scope. These are dissimilar than bean reach inwards Spring MVC together with don’t confuse betwixt Spring edible bean reach together with JSP variable reach if you lot are using Spring MVC inwards your Java spider web application. Rest of foreach loop volition live similar to foreach loop event of iterating over Collections inwards Java.
JSTL foreach event using varStatus variable
varStatus attribute declare yell of variable which holds electrical flow looping counter for foreach tag. It likewise break several useful information which you lot tin access using varStatus e.g. what is electrical flow row, whether you lot are inwards final row etc. Here is a code event of how to exercise varStatus inwards foreach JSTL tag on JSP:
<%-- JSTL foreach tag varStatus event to demo count inwards JSP --%>
<c:forEach var="window" items="${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 event inwards JSP
count: 1 Windows XP
count: 2 Windows 7
count: iii Windows 8
count: iv Windows mobile
</c:forEach>
Output:
JSTL foreach tag event 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 event inwards JSP JSTL
Another skillful matter of JSTL foreach tag is you lot tin nest foreach tag loop within about other foreach tag which is quite powerful agency of looping without using scriptlets inwards JSP. Here is an event of nesting foreach tag inwards JSP JSTL tag library:
<%-- JSTL foreach tag event 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: ${loopCounter.count}"/>
</c:forEach>
</c:forEach>
Output:
outer loop count: 1
inner loop count: 1
inner loop count: 2
outer loop count: 2
inner loop count: 1
inner loop count: 2
Complete JSTL foreach loop event inwards JSP
Here is consummate JSP page which shows how to exercise JSTL foreach tag for looping over String array . Similarly you lot tin loop over whatsoever Collection e.g. List or Set equally well.
<%@page import="java.util.List"%>
<%@page import="java.util.Arrays"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Welcome to JSTL foreach tag Example inwards JSP</title>
</head>
<body>
<h2>JSTL foreach tag event inwards JSP</h2>
<jsp:scriptlet>
String[] windows = novel String[]{"Windows XP", "Windows 7", "Windows 8", "Windows mobile"};
pageContext.setAttribute("windows", windows);
</jsp:scriptlet>
<%-- JSTL foreach tag event to loop an array inwards jsp --%>
<c:forEach var="window" items="${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 event 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 event 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 event inwards JSP
Windows XP
Windows 7
Windows 8
Windows mobile
</body>
</html>
Output:
JSTL foreach tag event inwards JSP
Windows XP
Windows 7
Windows 8
Windows mobile
That’s all on How to exercise JSTL forEach loop event inwards JSP page. We convey seen JSTL foreach tag event of Iterating or looping over Array, List, Collection together with nesting of 2 forEach loop which allows you lot to write powerful JSP pages without using whatsoever Java code.
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