问题
我一直在试图评估这个数组列表是否为空,但这些数据列表都没有编译:
<c:if test="${myObject.featuresList.size == 0 }">
<c:if test="${myObject.featuresList.length == 0 }">
<c:if test="${myObject.featuresList.size() == 0 }">
<c:if test="${myObject.featuresList.length() == 0 }">
<c:if test="${myObject.featuresList.empty}">
<c:if test="${myObject.featuresList.empty()}">
<c:if test="${myObject.featuresList.isEmpty}">
如何评估ArrayList是否为空?
#1 热门回答(226 赞)
empty是运营商。
<c:if test="${empty myObject.featuresList}">
#2 热门回答(63 赞)
还有功能标签,更灵活一点:
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>
<c:if test="${fn:length(list) > 0}">
Andhere's标签文档。