<html>?<head>? <title> 事件</title> ?? <script type="text/javascript">? ?function count(){? ? var a=document.getElementById("txt1").value;? ? var b=document.getElementById("txt2").value; var c=document.getElementById("select").value; var result=""; switch(c){ ? ?case "+"; ? ?result= a+b; ? ?break; ? ?case "-"; ? ?result= a-b; ? ?break; ? ?case "*"; ? ?result=a*b; ? ?break; ? ?default "/"; ? ?result= a/b; }? ?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()"/> <!--通過 = 按鈕來調(diào)用創(chuàng)建的函數(shù),得到結(jié)果-->?? ?<input type='text' id='fruit' /> ???</body></html>
請問這個代碼為什么運(yùn)行不了?
weibo_全世界都想弄垮你可我_0
2017-07-03 23:58:55