原生js操作option

  1 <script type="text/javascript">
  2     //    1.动态创建select
  3     function createSelect() {
  4         var mySelect = document.createElement("select");
  5         mySelect.id = "mySelect";
  6         document.body.appendChild(mySelect);
  7     }
  8 
  9     //2.添加选项option
 10 
 11     function addOption() {
 12         //根据id查找对象, 
 13         var obj = document.getElementById('mySelect');
 14         //添加一个选项 
 15         obj.add(new Option("文本", "")); //这个只能在IE中有效 
 16         obj.options.add(new Option("text", "value")); //这个兼容IE与firefox 
 17     }
 18 
 19     //3.删除所有选项option 
 20 
 21     function removeAll() {
 22         var obj = document.getElementById('mySelect');
 23         obj.options.length = 0;
 24     }
 25 
 26     //4.删除一个选项option 
 27 
 28     function removeOne() {
 29         var obj = document.getElementById('mySelect');
 30         //index,要删除选项的序号,这里取当前选中选项的序号 
 31         var index = obj.selectedIndex;
 32         obj.options.remove(index);
 33     }
 34 
 35     //5.获得选项option的值
 36 
 37     var obj = document.getElementById('mySelect');
 38     var index = obj.selectedIndex; //序号,取当前选中选项的序号 
 39     var val = obj.options[index].value;
 40 
 41     //6.获得选项option的文本
 42 
 43     var obj = document.getElementById('mySelect');
 44     var index = obj.selectedIndex; //序号,取当前选中选项的序号 
 45     var val = obj.options[index].text;
 46 
 47     //7.修改选项option 
 48 
 49     var obj = document.getElementById('mySelect');
 50     var index = obj.selectedIndex; //序号,取当前选中选项的序号 
 51     var val = obj.options[index] = new Option("新文本", "新值");
 52 
 53     //8.删除select 
 54 
 55     function removeSelect() {
 56         var mySelect = document.getElementById("mySelect");
 57         mySelect.parentNode.removeChild(mySelect);
 58     }
 59 </script>
 60 
 61 <!--//整个实例的完整代码如下:-->
 62 
 63 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//ZH-CN" "http://www.w3.org/TR/html4/strict.dtd">
 64 <html>
 65 
 66     <head>
 67         <meta http-equiv="Content-Type" content="text/html">
 68 
 69         <head>
 70             <script language=JavaScript>
 71                 function $(id) {
 72                     return document.getElementById(id)
 73                 }
 74 
 75                 function show() {
 76                     var selectObj = $("area")
 77                     var myOption = document.createElement("option")
 78                     myOption.setAttribute("value", "10")
 79                     myOption.appendChild(document.createTextNode("上海"))
 80                     var myOption1 = document.createElement("option")
 81                     myOption1.setAttribute("value", "100")
 82                     myOption1.appendChild(document.createTextNode("南京"))
 83                     selectObj.appendChild(myOption)
 84                     selectObj.appendChild(myOption1)
 85                 }
 86 
 87                 function choice() {
 88                     var index = $("area").selectedIndex;
 89                     var val = $("area").options[index].getAttribute("value")
 90                     if(val == 10) {
 91                         var i = $("context").childNodes.length - 1;
 92                         var remobj = $("context").childNodes[i];
 93                         remobj.removeNode(true)
 94                         var sh = document.createElement("select")
 95                         sh.add(new Option("浦东新区", "101"))
 96                         sh.add(new Option("黄浦区", "102"))
 97                         sh.add(new Option("徐汇区", "103"))
 98                         sh.add(new Option("普陀区", "104"))
 99                         $("context").appendChild(sh)
100                     }
101                     if(val == 100) {
102                         var i = $("context").childNodes.length - 1;
103                         var remobj = $("context").childNodes[i];
104                         remobj.removeNode(true)
105                         var nj = document.createElement("select")
106                         nj.add(new Option("玄武区", "201"))
107                         nj.add(new Option("白下区", "202"))
108                         nj.add(new Option("下关区", "203"))
109                         nj.add(new Option("栖霞区", "204"))
110                         $("context").appendChild(nj)
111                     }
112                 }
113 
114                 function calc() {
115                     var x = $("context").childNodes.length - 1;
116                     alert(x)
117                 }
118 
119                 function remove() {
120                     var i = $("context").childNodes.length - 1;
121                     var remobj = $("context").childNodes[i];
122                     remobj.removeNode(true)
123                 }
124             </script>
125 
126             <body>
127                 <div id="context">
128                     <select id="area" onchange="choice()">
129                     </select>
130                 </div>
131                 <input type=button value="显示" onclick="show()">
132                 <input type=button value="计算结点" onclick="calc()">
133                 <input type=button value="删除" onclick="remove()">
134             </body>
135 
136 </html>
137 
138 
139 <!--改进版:-->
140 
141 <script type="text/javascript">
142     //改进版:在select中添加、修改、删除option元素 
143 
144     function watch_ini() { // 初始 
145         for(var i = 0; i < arguments.length; i++) {
146             var word = document.createElement("OPTION");
147             word.text = arguments[i];
148             watch.keywords.add(word); // watch. is form name 
149         }
150     }
151 
152     function watch_add(f) { // 增加 
153         var word = document.createElement("OPTION");
154         word.text = f.word.value;
155         f.keywords.add(word);
156     }
157 
158     //但上述 add() 方法只在IE下有效,为兼容FF和Opera,对上述代码进行了一下改进,改动后代码如下:
159 
160     function watch_ini() { // 初始 
161         for(var i = 0; i < arguments.length; i++) {
162             var oOption = new Option(arguments[i], arguments[i]);
163             document.getElementById("MySelect")[i] = oOption;
164         }
165     }
166 
167     function watch_add(f) { // 增加 
168         var oOption = new Option(f.word.value, f.word.value);
169         f.keywords[f.keywords.length] = oOption;
170     }
171 </script>
172 
173 <!--整个实例的完整代码如下:-->
174 
175 <!doctype html public "-//w3c//dtd html 4.0 transitional//en">
176 <html>
177 
178 <head>
179     <title>javascript select options text value</title>
180     <meta name="keywords" content="javascript select options text value add modify delete set">
181     <meta name="description" content="javascript select options text value add modify delete set">
182     <script language="javascript">
183         <!-- 
184         function watch_ini() { // 初始 
185             for(var i = 0; i < arguments.length; i++) {
186                 var oOption = new Option(arguments[i], arguments[i]);
187                 document.getElementById("MySelect")[i] = oOption;
188             }
189         }
190 
191         function watch_add(f) { // 增加 
192             var oOption = new Option(f.word.value, f.word.value);
193             f.keywords[f.keywords.length] = oOption;
194         }
195 
196         function watch_sel(f) { // 编辑 
197             f.word.value = f.keywords[f.keywords.selectedIndex].text;
198         }
199 
200         function watch_mod(f) { // 修改 
201             f.keywords[f.keywords.selectedIndex].text = f.word.value;
202         }
203 
204         function watch_del(f) { // 删除 
205             f.keywords.remove(f.keywords.selectedIndex);
206         }
207 
208         function watch_set(f) { // 保存 
209             var set = "";
210             for(var i = 0; i < f.keywords.length; i++) {
211                 set += f.keywords[i].text + ";";
212             }
213             confirm(set);
214         }
215         //-->
216     </script>
217 </head>
218 
219 <body>
220     <form name="watch" method="post" action="">
221         <select id="MySelect" name="keywords" size="10" onchange="watch_sel(this.form)"></select><br>
222         <script language="javascript">
223             <!-- 
224             watch_ini("", "", "", "", "", "", ""); // 初始关键词 
225             //-->
226         </script>
227         <input type="text" name="word" /><br />
228         <input type="button" value="增加" onclick="watch_add(this.form);" />
229         <input type="button" value="修改" onclick="watch_mod(this.form);" />
230         <input type="button" value="删除" onclick="watch_del(this.form);" />
231         <input type="button" value="保存" onclick="watch_set(this.form);" />
232     </form>
233 </body>
234 
235 </html>
236 
237 <script>
238     //用一个字符串创建一个数组方法:
239     function spli() {
240         datastr = "2,2,3,5,6,6";
241         varstr = newArray();
242         str = datastr.split(",");
243         for(i = 0; i < str.length; i++) {
244             document.write(str[i] + "<br/>");
245         }
246     }
247     spli();
248 </script>
原文地址:https://www.cnblogs.com/libin6505/p/7405986.html