<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<script type="text/javascript">
function numb(){
var num1 = parseInt(Math.round((Math.random())*20));
document.getElementById('num1').innerHTML = num1;
}
</script>
</head>
<body onload="numb()">
<div>
<span id="num1"></span> + <span id="num1"></span> = <br>
</div>
</body>运行结果
为啥只出现了一个数，问题出在哪了老铁们