var age = 14;

 window.coloer = "pink";

 console.log(delete window.age);//false 使用var语句添加的window属性的[[Configurable]]的特性的值为false，因此不能通过delete操作符删除。

 console.log(delete window.color);//true

 console.log(window.age);//

 console.log(window.color);//undefined

 var newValue = oldValue;//报错：oldValue is not defined 

 var newValue = window.oldValue;//不会报错，是一次属性查询

 console.log(newValue);//undefined

 var leftPos = (typeof window.screenLeft == "number" ) ? window.screenLeft : window.screenX;

 var topPos = (typeof window.screenTop == "number" ) ? window.screenTop : window.screenY;

 console.log(leftPos,topPos);/*这里浏览器窗口位置改变，坐标也会相应的改变，在Chrome浏览器中，全屏世的坐标是(0,0)*/

 window.moveTo(0,0);/*每刷新一次，移动到(0,0)，即屏幕左上角*/

 window.moveBy(0,100);/*每刷新一次，向下移动100px*/

 window.moveTo(200,300);/*每刷新一次，移动到(200,300)*/

 window.moveBy(-50,0);/*每刷新一次，向左移动50个像素*/

 ar pageWidth = window.innerWidth,

     pageHeight = window.innerHeight;

 if(typeof pageWidth != "number"){

     if(document.compatMode == "CSS1Compat"){

         pageWidth = document.documentElement.clienWidth;

         pageHeight = document.documentElement.clienHeight;

     }else{

         pageWidth = document.body.clienWidth;

         pageHeight = document.body.clienHeight;

     }

 }

 console.log(pageWidth,pageHeight);

 window.resizeTo(100,100);

 window.resizeBy(100,50);/*每刷新一次，宽度增加100px(向右)，高度增加50px(向下)*/