為什么不顯示呢？
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>返回值函數(shù)</title>
<script type="text/javascript">
? function? app2(x,y)
? { var sum,x,y;
? ? sum = x * y;
? ? ?return sum();
? }
?req1=app2(5,6);
?req2=app2(2,3);
?sumq=req1+req2;
document.write("req1的值:"+req1+"<br/>");
document.write("req2的值:"+req2+"<br/>");
document.write(req1+"與"+req2+"和:"+sumq);
</script>
</head>
<body>
</body>
</html>
2018-09-14
1.函數(shù)返回值return sum；sum是一個(gè)變量，存儲(chǔ)了x和y的積，加了括號(hào)無法識(shí)別
2018-09-14
非常感謝