if语句的实现：
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>c:if标签实例</title>
<%
int a=8;
request.setAttribute("aa", a);
%>
<c:if test="${aa>6}">
a>6
</c:if>
</head>
<body>
</body>
</html>ifelse语句的实现：
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>ifelse标签实例</title>
</head>
<body>
<%
int a=7;
request.setAttribute("aa", a);
%>
<c:choose>
<c:when test="${aa<5 }">a<5</c:when>
<c:otherwise>a>5</c:otherwise>
</c:choose>
</body>
</html>for语句的实现：
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>for标签实例</title>
</head>
<body>
<c:forEach var="i" begin="0" end="4">
${i }<br>
</c:forEach>
</body>
</html>