jstl概述
jstl概述
if_常用标签
if_常用标签
<%@ page import="java.util.ArrayList" %>
<%@ page contentType="text/html;charset=UTF-8" pageEncoding="utf-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<title>$Title$</title>
</head>
<body>
<%
ArrayList<Object> list = new ArrayList<>();
list.add("aaaaaaa");
request.setAttribute("list", list);
request.setAttribute("num", 3);
%>
<h1>1111111111</h1>
<c:if test="${not empty list}">
遍历list----11
</c:if>
<br>
<c:if test="${num % 2 != 0 }">
${num} 是奇数
</c:if>
<br>
<c:if test="${ num % 2 == 0}">
${ num } 是偶数
</c:if>
</body>
</html>
JSTL_常用标签_choose
图片.png
<%@ page import="java.util.ArrayList" %>
<%@ page contentType="text/html;charset=UTF-8" pageEncoding="utf-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<title>$Title$</title>
</head>
<body>
<%
request.setAttribute("num", 89);
%>
<c:choose>
<c:when test="${num==1}"> 星期一 </c:when>
<c:when test="${num==2}"> 星期二 </c:when>
<c:when test="${num==3}"> 星期三 </c:when>
<c:when test="${num==4}"> 星期四 </c:when>
<c:when test="${num==5}"> 星期五 </c:when>
<c:when test="${num==6}"> 星期六 </c:when>
<c:when test="${num==7}"> 星期日 </c:when>
<c:otherwise>输入有误</c:otherwise>
</c:choose>
</body>
</html>
JSTL_常用标签_foreach()
foreach
遍历容器
<%@ page import="java.util.ArrayList" %>
<%@ page contentType="text/html;charset=UTF-8" pageEncoding="utf-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<title>$Title$</title>
</head>
<body>
<%
ArrayList<Object> list = new ArrayList<>();
list.add("aaa");
list.add("bbb");
list.add("ccc");
list.add("ddd");
request.setAttribute("list",list);
%>
<c:forEach begin="1" end="10" var="i" step="1">
${i}-->
</c:forEach>
<c:forEach items="${list}" var="str" varStatus="s">
${str}--${s.index}--${s.count}
</c:forEach>
</body>
</html>
