You said brackets. Are you talking about curly braces instead? "{" and "}".
Curly braces define a local scope. It can be used simply for code readability, or you can also use it to limit the scope of local variables:
- (void)viewDidLoad
{
[super viewDidLoad];
{
//local variables inside these braces are only defined inside this set of braces
NSString *scratchString;
int count = 1;
scratchString = @"foo";
}
{
//The string scratchString below is a different local variable than
//The one defined above.
NSString *scratchString;
int count = 5;
scratchString = @"bar";
}
}