- <!DOCTYPE html>
- <html>
- <head>
- <title>
- 事件
- </title>
- <script type="text/javascript">
- function count() {
- //获取第一个输入框的值
- var txt1 = document.getElementById("txt1").value;
- //获取第二个输入框的值
- var txt2 = document.getElementById("txt2").value;
- //获取选择框的值
- var select = document.getElementById("select").value;
- var result = "";
- //获取通过下拉框来选择的值来改变加减乘除的运算法则
- switch (select) {
- case "+":
- result = parseInt(txt1) + parseInt(txt2);
- break;
- case "-":
- result = parseInt(txt1) - parseInt(txt2);
- break;
- case "*":
- result = parseInt(txt1) * parseInt(txt2);
- break;
- default:
- result = parseInt(txt1) / parseInt(txt2);
- }
- //设置结果输入框的值
- document.getElementById("fruit").value = result;
- }
- </script>
- </head>
- <body>
- <input type='text' id='txt1' />
- <select id='select'>
- <option value='+'>
- +
- </option>
- <option value="-">
- -
- </option>
- <option value="*">
- *
- </option>
- <option value="/">
- /
- </option>
- </select>
- <input type='text' id='txt2' />
- <input type='button' value='=' onclick="count()" />
- <!--通过=按 钮来调用创建的函数,得到结果-->
- <input type='text' id='fruit' />
- </body>
- </html>
来源: