javascript - Split a string of file input field -

I need to get a value in a form from the input field, I just need the filename, the string looks like this :

  var str = 'C: \ users \ user \ desktop \ file_name.ext';   
 If I try to run (yes, the backslash is saved)  
  str.split (\\) [str.length-1]   
 This does not work, because the slash in the string is not saved. Simple  console.log (str)  gives me  C: UsersUserDesktopile_name.ext  and you see how the problem is where do I get around it?  
 
 
  'c: \ user \ user \ desktop \ file_name .ext'.split (/ \\ | //) Pop () ;.   
 Backlash escapes I am confusing people by escaping my backslash. The above string is "like".