jquery :checked(过滤选择器) 和 空格:checked(后代选择器)【转】

jquery 过滤选择器 和 后代选择器

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ include file="/WEB-INF/jsp/common/base.jsp"%>


<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <jsp:include page="/WEB-INF/jsp/common/baseJS.jsp"></jsp:include>
    <jsp:include page="/WEB-INF/jsp/common/baseCSS.jsp"></jsp:include>
<title>checkbox&nbsp;radio.jsp</title>
</head>
<body>
    <form action="">
        <input type="radio" name="sex" value="male" checked="checked"/> Male
        <input type="radio" name="sex" value="female" /> Female
        <hr/>
        I have a bike:
        <input type="checkbox" name="vehicle" value="Bike" />
        <br />
        I have a car:
        <input type="checkbox" name="vehicle" value="Car" checked="checked" />
        <br />
        I have an airplane:
        <input type="checkbox" name="vehicle" value="Airplane" />
    </form>
    <button class="radio">radio</button>
    <button class="checkbox">checkbox</button>
    <button class="all">__all__</button>
    
    <script type="text/javascript">
        $(function(){
            $(".radio").click(function() {
                //form:checked一定不要加空格,意为过滤选择器,即选取:checked的input[name='sex']的元素
                var $checkedObj = $("input[name='sex']:checked");
                console.log("被选中的radio共有"+ $checkedObj.size() +"个");
                $.each( $checkedObj , function(index,obj){
                    alert("第"+index+"个被选中的radio的值为 "+$(obj).val());
                });
            });
            
            
            $(".checkbox").click(function() {
                //form:checked一定不要加空格,意为过滤选择器,即选取:checked的input[name='vehicle']的元素
                var $checkedObj = $("input[name='vehicle']:checked");
                console.log("被选中的checkbox共有"+ $checkedObj.size() +"个");
                $.each($checkedObj,function(index,obj){
                    alert("第"+index+"个被选中的checkbox的值为 "+$(obj).val());
                });
            });
            
            
            $(".all").click(function() {
                //form :checked一定要加空格,意为后代选择器,即form的内容中带有:checked的元素
                var $checkedObj = $("form :checked");
                console.log("被选中的元素共有"+ $checkedObj.size() +"个");
                $.each($checkedObj,function(index,obj){
                    alert("第"+index+"个被选中的元素的值为 "+$(obj).val());
                });
            });
        })
    </script>
</body>
</html>

补充说明 $.each(list,function(index,obj)){...}用法

http://www.cnblogs.com/cdemo/p/4142695.html

$.each可以遍历element dom元素正如上例中用法,也可以遍历jsonArray如下.

//如果myJsonArray = [{ id: 1, department: '开发部' }, { id: 2, department: '销售部' }, {id:3,department:'行政部'}];
 $.each(myJsonArray,function(index,obj){
    alert("第"+index+"个被选中的元素的值为 "+obj.department);
});
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原文地址：https://www.cnblogs.com/whatlonelytear/p/4748276.html