JS實現二級聯動 (createTextNode，createElement )
阿新 • • 發佈：2018-12-17
JS中只有陣列，沒有集合
陣列長度=角標+1 長度可變
cities[0],cities[1],cities[2],cities[3]
cities[100] 長度是101 而不是5
<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title></title> <script> //1.建立一個二維陣列用於儲存省份和城市 var cities = new Array(3); cities[0] = new Array("武漢市","黃岡市","襄陽市","荊州市"); cities[1] = new Array("長沙市","郴州市","株洲市","岳陽市"); cities[2] = new Array("石家莊市","邯鄲市","廊坊市","保定市"); cities[3] = new Array("鄭州市","洛陽市","開封市","安陽市"); function changeCity(val){ //7.獲取第二個下拉列表 var cityEle = document.getElementById("city"); //9.清空第二個下拉列表的option內容 cityEle.options.length=0; //2.遍歷二維陣列中的省份 for(var i=0;i<cities.length;i++){ if(val==i){ for(var j=0;j<cities[i].length;j++){ var textNode=document.createTextNode(cities[i][j]); var opEle = document.createElement("option"); opEle.appendChild(textNode); cityEle.appendChild(opEle); } } } } </script> </head> <body> <form action="#"> <select onchange="changeCity(this.value)"> <option>--請選擇--</option> <option value="0">湖北</option> <option value="1">湖南</option> <option value="2">河北</option> <option value="3">河南</option> </select> <select id="city"> </select> </form> </body> </html>