What does the asterisk before variable signify?

Does anyone开发者_如何转开发 know where I can find documentation about what the asterisk before variables is used for. I don't understand it and it's starting to become a problem because I have noticed you don't need it for all types for e.g. BOOL doesn't return it.

It's C notation for a pointer.

You don't need it for a BOOL because it is not an object and so it isn't passed by reference

Have a look at the Introduction to Objective-C part of the documentation.