[dan1234]

I do type a lot more square brackets in ObjC than any other language, but I find that I type a lot more generally due to the increased length of many method names in ObjC (or I would do if autocomplete didn't do it for me).

(Simple) Example:

  PHP:
  $myString = sprintf('Total: %.2f', $myFloat); 

  ObjC:
  NSString *myString = [NSString stringWithFormat:@"Total: %.2f", myFloat]; 

Maybe this is the reason these characters don't score too highly in overall frequency? I have no answer for the high frequency of '/'.

[k-mcgrady]

That's a good point. Regarding the '/' I'm betting the code sample was very well commented.

[alpb]

I bet the code sample was from Apple's demo projects so there were like 100 lines of licensing/copyright at the top of each source file.