為什么我這輸出是NAN？
<!DOCTYPE?HTML>
<html>
<head>
<meta?http-equiv="Content-Type"?content="text/html;?charset=utf-8"?/>
<title>定義函數(shù)</title>
<script?type="text/javascript">
?function??sub2(a,b)
?{
???var?aaa?=?a-b;
???document.getElementById("sss").innerHTML+=aaa;
?}
?sub2(3,2);
?sub2(4,2);
?sub2(5,2);
</script>
</head>
<body>
<input?type="button"?value="點(diǎn)擊我"?onclick="sub2()"?/>
?<div?id="sss"></div>
</body>
</html>
2015-06-05
肯定是NaN啊，你在點(diǎn)擊事件中 都沒(méi)有傳參數(shù)，那怎么運(yùn)算