<%@page import="java.util.Map"%>
<%@page import="java.util.HashMap"%>
<%@ page language="java" pageEncoding="utf-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Insert title here</title>
</head>
<body>
<h1>jstl标签库,c:set.</h1>
//1. 将属性存入某一个作用域<br/>
<c:set var="name" value="李四" scope="page"></c:set>
${name }
<br/>
//2.修作用域中改已有属性<br/>
<c:set var="name" value="李四修改了" scope="page"></c:set>
${name }
<br/>
// 3. 修改作用域中map集合中的属性
<%
Map map=new HashMap();
map.put("name","吴京");
map.put("age",61);
pageContext.setAttribute("map1", map);
%>
<br/>
${map1.name }
${map1.age }
<br/>
<c:set target="${map1 }" property="name" value="吴京被修改"/>
${map1.name }
</body>
</html>
===================================================
<%@ page language="java" pageEncoding="utf-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<html>
<head>
<title>Insert title here</title>
</head>
<body>
<h2>jstl标签库,c:if.</h2>
<c:if test="${5>6 }">yes</c:if>
<c:if test="${!(5>6) }">no</c:if>
</body>
</html>
==================================================
<%@page import="java.util.Map"%>
<%@page import="java.util.HashMap"%>
<%@page import="java.util.List"%>
<%@page import="java.util.ArrayList"%>
<%@ page language="java" pageEncoding="utf-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<html>
<head>
<title>Insert title here</title>
</head>
<body>
//1. 遍历数组或集合中的元素<br/>
<%
List list=new ArrayList();
list.add("北京");
list.add("上海");
list.add("浙江");
pageContext.setAttribute("list", list);
%>
<c:forEach items="${list }" var="i">${i }</c:forEach>
<br/>
//2. 遍历map集合中的元素<br/>
<%
Map map=new HashMap();
map.put("name","吴京");
map.put("age",61);
pageContext.setAttribute("map1", map);
%>
<c:forEach items="${map1}" var="entry" >
${entry.key }:${entry.value }<br/>
</c:forEach>
</body>
</html>
====================================================
<%@ page language="java" pageEncoding="utf-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
</head>
<body>
/* 3. 遍历1--100之间的奇数 ,位置是3的倍数设置为红色*/ <br/>
<c:forEach begin="1" end="100" step="2" var="i" varStatus="status">
<%-- 3的倍数设置为红色--%>
<c:if test="${status.count %3 ==0 }">
<span style="color:red">
${ i }
</span>
</c:if>
<%-- 不是3的倍数打印出来 --%>
<c:if test="${status.count %3 !=0 }">
${ i }
</c:if>
<%-- 判断i是否是最后一个，如果不是就加上分号 --%>
<c:if test="${ !status.last}">
;
</c:if>
</c:forEach>
</body>
</html>
