Q:

if([aString writeToFile: @"outfile" atomically: YES])

For some code like
if([aString writeToFile: @"outfile" atomically: YES])

I am wondering if atomically is a parameter or a parameter name?

A:

Parameter name would be what the variable is called. I guess you could call it a parameter but parameter is a very general term in my opinion.
I think the correct thing to say is that it's the method name, It's a part of it. Just that you can have parameters in between to kind of split it up.
And btw this is one of the things I love in objective c, the code gets so readable thanks to it :)

