iphone sdk 3.0 - What is the difference between .tag and tag -

i have query on this. please @ sample code below:

uibutton *button;     button.tag = 1; 

and

int =  (int)[(uibutton*)sender tag]; 

the first line set tag number 1 button variable, using .tag method. , in second line, used (int)[(uibutton*)sender tag]; extract , cast sender integer value. question be, difference between .tag , tag method?

there should no difference. before objective c 2.0, dot methods didn't exist; these added, function shortcuts longer bracketed call.

in particular code example, in first code block, button doesn't hold pointer button. you'd need call

uibutton *button = [uibutton buttonwithtype:uibuttonroundedrect]; button.tag = 1; 

this set tag 1. second code block takes existing button , extracts tag int, indicated. better example of parallel methods be:

button.tag = 1; , [button settag:1];, or

int tag = button.tag; , int tag = [button tag];