chrome中针对不同实例的JavaScript函数返回结果有所不同

Question

First i executed the below script in chrome console

 var x = 1; if (function f(){}) { x += typeof f; } x; 

I got '1undefined' as result.

Then i executed function f(){} in console and again executed the above script,then i got the result '1function'. Now i opened another instance of chrome browser and again run the above script i am getting '1object'.

My question is why i am getting different result.

step1:- Run the above code snippet in chrome console. Result is 1undefined

step 2:-Run function f(){} in chrome console.Result is 1function

step 3:-open another instance of chrome and run the above snippet again.Result is 1object

below that 1object ..i have this text 'Application Cache Checking event'

Answer 1

When you open another tab of chrome, it by defaults open Google home page. If you execute the script there from console even for the first time, it will print 1object. As there is a javascript file on that page that define a variable F as object. You can check it here https://www.google.co.in/_/chrome/newtab?espv=2&ie=UTF-8

As most sites minify js files, the variable are named A,B.....

Its not magic :)