what does [native code]mean in js?

Question

I was checking all the properties of window object, and I found all the window methods to be
function(){[native code]}
what does native code mean here? is it possible to see it?

https://code.sololearn.com/W79R136QRb8a/?ref=app

Answer 1

the WebKit and Firefox developers have coded up that functionality in C or C++, not JavaScript. 

https://stackoverflow.com/questions/11234664/what-does-native-code-mean

ViewVC Repository Listing
https://src.chromium.org/viewvc

Answer 2

Native code means it is not written in js but maybe in c or c++
I would search for this function in google.
Maybe this article helps you:
https://stackoverflow.com/questions/9103336/how-can-i-read-native-code-javascript-functions/9103381