JS实现三级联动

js实现三级联动

無、小白

2724人浏览 · 2022-08-01 10:35:47

無、小白 · 2022-08-01 10:35:47 发布

js实现三级联动

三级联动就是平时网页上需要选择的省市县对应位置的下拉栏模块，当选择好省位置后市的下拉栏更新为已选省的，县类似。在日常生活中我们经常使用比如各类购物软件的地址栏，各种平台的认证填写的家挺住址都会用到三级联动，本次内容为使用JS实现简单的三级联动。

<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		//引入jQuery cdn加速
		<script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script>
	</head>
	<body>
	//创建三个下拉框这里为了方便id定义为a、b、c
		<select name="" id="a">
		</select>
		<select name="" id="b">
		</select>
		<select name="" id="c">
		</select>
		<script type="text/javascript">
		//创建两个对象用来存储地名
		var obj={
			"河南":["郑州","周口","商丘","安阳","南阳"],
			"云南":["大理","丽江","昆明","玉溪"],
			"山东":["菏泽","青岛","济南","烟台"]
				}
			var obj1={
					"郑州":["金水区","新郑市","二七区","中牟县"],
					"周口":["鹿邑县","郸城县","21","121"],
					"商丘":["1223","321","321","123"],
					"安阳":["滑县","21","321"],
					"南阳":["111","222","333","444"],
					"大理":["AAA","BBB","CCC","DDD"],
					"丽江":["EEE","FFF","GGG","HHH"],
					"昆明":["III","JJJ","KKK","RRR"],
					"玉溪":["MMM","NNN","XXXX"],
					"菏泽":["曹县","HEHE","HAHA","HEIHEI"],
					"青岛":["XIXI","LALA","CA","WC"],
					"济南":["猪娃县","猪头县","猪县"],
					"烟台":["猪奶子县","猪脑县","猪肘子县"]
					
				}
				//for-in循环输出obj的Key
				for ( var x in obj) {
					$("<option>"+x+"</option>").appendTo("#a");
				}
				//创建一个改变事件获取框中被选中的地名获得值
				$("#a").change(function(){
					var arr=$(this).val();
					//获取的值为obj的key 这里将obj的值赋给arr
					var arr1=obj[arr];
					//清除上次点击打印出来的值
					$("#b").html("");
					//循环输出arr的值
					for(var i=0;i<arr1.length;i++){
						$("<option>"+arr1[i]+"</option>").appendTo("#b");
					}
					//虚拟点击
					$("#b").change();
				})
				//基本同上不过是利用obj的值当作obj1的key获取obj1的值
				$("#b").change(function(){
					var arr2=$(this).val();
					var arr3=obj1[arr2]
					$("#c").html("");
					for(var j=0;j<arr3.length;j++){
						$("<option>"+arr3[j]+"</option>").appendTo("#c");
					}
				})
					//虚拟点击点击
					$("#a").change();
					
		</script>
	</body>
</html>