效果圖:html
、this
代碼: code
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>三級聯動</title> <style> * { margin: 0px; padding: 0px; } </style> </head> <body> 省:<select name="" id="pre" style="width: 100px;" onchange="chg(this);"> <option value="-1">請選擇</option> </select> 市: <select name="" id="city" style="width: 100px;" onchange="chg2(this);"> </select> 區: <select name="" id="area" style="width: 100px;"> </select> <script> var pres = ["北京 ", "上海 ", "山東 "]; var cities = [ ["東城 ", "海淀 ", "朝陽 "], ["浦東 ", "徐匯 ", "嘉定 "], ["青島 ", "菏澤 ", "煙臺 "] ]; var area = [ [ ["東城一 ", "東城二 ", "東城三 "], ["海淀一 ", "海淀二 ", "海淀三 "], ["朝陽一 ", "朝陽二 ", "朝陽三 "], ], [ ["浦東一 ", "浦東二 ", "浦東三 "], ["徐匯一 ", "徐匯二 ", "徐匯三 "], ["嘉定一 ", "嘉定二 ", "嘉定三 "], ], [ ["青島一 ", "青島二 ", "青島三"], ["菏澤一 ", "菏澤二", "菏澤三"], ["煙臺一 ", "煙臺二", "煙臺三"], ], ]; var preEle = document.getElementById("pre"); var cityEle = document.getElementById("city"); var areaEle = document.getElementById("area"); /*省份遍歷*/ for (var i = 0; i < pres.length; i++) { /*給option添加值,value值,其中pres[i]爲值,i爲value值*/ var op = new Option(pres[i], i); preEle.options.add(op); }; /*點擊省份*/ var val01; function chg(obj) { val01 = obj.value; var citiesval = cities[val01]; var areaval = area[val01][0]; /*清空市區*/ cityEle.options.length = 0; areaEle.options.length = 0; /*遍歷市*/ for (i = 0; i < citiesval.length; i++) { var op = new Option(citiesval[i], i); cityEle.options.add(op); } /*遍歷區*/ for (i = 0; i < areaval.length; i++) { var op = new Option(areaval[i], i); areaEle.options.add(op); } }; /*點擊市*/ function chg2(obj) { var val = obj.value; var areav = area[val01][val]; areaEle.options.length = 0; /*遍歷區*/ for (i = 0; i < areav.length; i++) { var op = new Option(areav[i], i); areaEle.options.add(op); } } </script> </body> </html>