版权声明：任先阳 任 先 阳 任先 先阳，ifgm.cn、www.ifgm.cn、nvcc.cc、www.nvcc.cc、sbfox.com、www.sbfox.com https://blog.csdn.net/qq_39571197/article/details/86624592
结论：全局性的使用VAR、FUNCTION声明，都会挂载(覆盖)到window对象
1、测试如下代码
var open = 2;
console.log(open);
console.log(window.open);
console.log(window); // 查看 open 属性function open(){
}
open.info = "123456";
console.log(open.info);
console.log(window.open.info);
console.log(window); // 查看 open 属性【完】
https://www.imooc.com/qadetail/137684，可以看下这个问题，只不过是重写了open方法，导致了死循环...
<!DOCTYPE html >
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title>浏览器对象_编程练习</title>
<script type="text/javascript">
function back() {
window.history.back();
}
function change() {
setTimeout("open2()", 5000);
}
function open2() {
//location.assign("http://www.imooc.com");
window.open('http://www.imooc.com', '_self');
//这里如果用window.open.('http://www.imooc.com');就不行了
}
change();
</script>
</head>
<body>
<input type="button" value="返回上页面" onclick="back()"/>
</body>
</html>