Question

For example, sometimes there’s an import like this:

#import <Cocoa/Cocoa.h>

and sometimes the import looks like this:

#import "Foo.h"

Now what’s the difference there? The first is in < > tag things, and the second is in doublequotes. What does the first do? Is that used for pre-compiled files like frameworks which are compiled already? Or what’s the point there?

Answer 1

The angle brackets indicate system includes (which looks in a different set of directories).

The double-quoted include is for non-system includes… (i.e. yours). It will look in the current directory first, and then other (command line specified) include directories.

There’s a pretty good set of documentation here:

http://developer.apple.com/mac/library/documentation/DeveloperTools/gcc-4.0.1/cpp/Header-Files.html