<!DOCTYPE html> <html> <head> <title> 事件</title> <script type="text/javascript"> function count(){ var one=document.getElementById("txt1").value; var two=document.getElementById("txt2").value; var a=doucument.getElementById("select").value; var num; switch(a){ case "+": num=parseInt(one)+parseInt(two); break; case "-": num=parseInt(one)-parseInt(two); break; case "*": num=parseInt(one)*parseInt(two); break; case "/" : num=parseInt(one)/parseInt(two); break; } document.getElementById("fruit").value=num; } </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>
var a=doucument.getElementById("select").value;?这一行的document,多写了个u。第9行