CODEWITHSUNDEEP
objective-c
DWB
DWB

Reputation: 1554

Why doesn't a Boolean have to point to an object

When implementing a getter or setter for an NSString it appears as

-(NSString *)nameOfSomething

however when you get or set a Boolean you don't us an asterisks to point to something

-(BOOL)nameOfSomething

I was wondering why you have to do this? Shouldn't the asterisks still be needed in order to point? Is there a certain reason a Boolean doesn't need one?

Thanks

Upvotes: 3

Views: 119

Answers (3)

Lay González
Lay González

Reputation: 2985

It is a primitive type, just like an int. In theory, it could be an object, but it is so a very simple concept that makes it of almost no use.

Consider this analogies. (Left for primitive types, right for classes)

int  : Integer    (Integer from java)
BOOL :  ---
 --- : NSString

and so on.

If you really require an object, make a wrapper.

Upvotes: 1

matt
matt

Reputation: 535167

It's a good idea to learn C before trying to program iOS, because you're going to be using Objective-C, and Objective-C is C. There is a difference between a plain data type and a pointer. The asterisk has to do with pointers. (Objective-C "object" types are all pointers, but C has other types.)

The most important aspects of C needed for iOS programming are discussed here:

http://www.apeth.com/iOSBook/ch01.html

As that chapter explains, a BOOL is like an NSInteger - it's just a number, not an object.

Upvotes: 4

Anoop Vaidya
Anoop Vaidya

Reputation: 46543

BOOL are just signed char, you don not take its address/reference.

You directly assign to it.

If you see its definition which is as :

typedef signed char     BOOL; 
// BOOL is explicitly signed so @encode(BOOL) == "c" rather than "C" 
// even if -funsigned-char is used.

#if __has_feature(objc_bool)
#define YES             __objc_yes
#define NO              __objc_no
#else
#define YES             ((BOOL)1)
#define NO              ((BOOL)0)
#endif

You use to see its value by %d not %@.

Upvotes: 0

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