<!DOCTYPE?html>
<html>
?<head>
??<title>?事件</title>??
??<script?type="text/javascript">
???function?count(){
????//獲取第一個輸入框的值
????????a=document.getElementByld(txt1).value;
???? //獲取第二個輸入框的值
???? b=document.getElementByld(txt2).value;
???? //獲取選擇框的值
???? fuhao=document.getElementByld(select).value;
???? ???sum=parseFloat(a)+parseFloat(b);
???????jian=parseFloat(a)-parseFloat(b);
???????cheng=parseFloat(a)*parseFloat(b);chu=parseFloat(a)/parseFloat(b);
???? if(fuhao=="+"){
???? ????document.getElementById("fruit").value=sum;
???? }
???? if(fuhao=="-"){
???? ????
???? ????document.getElementById("fruit").value=jian;
???? }
???? if(fuhao=="*"){
???? ??
???? ????document.getElementById("fruit").value=cheng;
???? }
???? if(fuhao=="/"){
???? ???
???? ????document.getElementById("fruit").value=chu;
???? }
???? //獲取通過下拉框來選擇的值來改變加減乘除的運算法則
????//設(shè)置結(jié)果輸入框的值?
???}
??</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>
為什么結(jié)果出不來？求解答。。
像個好人
2017-07-28 08:36:55