<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Random对象</title>
</head>
<body>
本次选择的颜色是：<span id="color"></span>
<input type="button" value="选择颜色" onclick="selColor();">
<script type="text/javascript">
function selColor(){
var color=new Array("红色","黄色","蓝色","绿色","紫色","橙色","青色");
var num=Math.ceil(Math.random()*7)-1;
//Math.ceil(Math.random()*7)-1这一句是什么意思啊？
document.getElementById("color").innerHTML=color[num];
}
</script>
</body>
</html>
//Math.ceil(Math.random()*7)-1这一句是什么意思啊？详解必采纳
