JavaScript-事件【二级联动】
JavaScript - 事件 practice2
题目:
<script type="text/javascript"> window.onload = function(){ //创建省份和城市数组,备用 var provinceArr = ["湖南","湖北","广东"]; var cityArr = ["长沙,株洲,湘潭,益阳,张家界", "武汉,宜昌,恩施,黄石","广州,东莞,惠州,深圳"]; //通过ID获取select标签 var selProvince = document.getElementById("province"); var selCity = document.getElementById("city"); //新建option标签,并添加进select标签中 for(var i=0;i<provinceArr.length;i++) { var opP = document.createElement("option"); opP.value = i; opP.innerHTML = provinceArr[i]; selProvince.appendChild(opP); } //添加select标签的事件 selProvince.onchange = function(){ //刷新城市下拉列表 selCity.options.length=1; //获取添加事件的select标签当前选择的项(option)的value var selIndex = this.value; if(selIndex>=0){ //分割,城市数组 var cityArrs = cityArr[selIndex].split(","); for(var j=0;j<cityArrs.length;j++){ var opC = document.createElement("option");
opC.value = cityArrs[j];opC.innerHTML = cityArrs[j]; selCity.appendChild(opC); } } } }</script>
<body> <h2>选择所在的省份及城市</h2> 省份: <select id="province"> <option>-请选择省份-</option> </select> 城市: <select id="city"> <option>-请选择城市-</option> </select> </body>