What's the difference between dot syntax and square bracket syntax?

Question

I am going through some walkthroughs fpr Objective-C and I got to many places where I raised my eyebrows. I would love to get them down.

1. Is there a fundamen

Answer 1

I'm not sure what kind of distinction you're trying to make between "message sending" and "method calling", since they're two ways of describing the same thing. The dot syntax is just a shortcut for calling getters and setters, that is:

[foo length]
foo.length

are exactly the same, as are:

[foo setLength:5]
foo.length = 5

You should generally only use the dot syntax when you're using getters and setters; use the square bracket syntax for all of your other method calls.

For your second question: this is how dynamic typing works. Any type declarations you put in your code are hints to the compiler; your Objective-C method calls will always work as long as the objects respond to them.