private property in objective c

Question

I am writing class in Objective c.

and I want a private property from type double in my main view controller.

my code: MainViewController.m

#import "MainViewController.h"

@interface MainViewController ()

@property (nonatomic) BOOL x;

@end

@implementation MainViewController

now , i know taht Automatic Property Synthesis With Xcode 4.4 but if i dont write @synthesize x; i can access to my property "x" only with "self.x" or "_x"

and if i write @synthesize x

i can access with just write "x".

i know it is a simple question ,but I really want to understand what is happening in the code behind, and the essential difference between the two approaches.

thanks

The default is actually `@synthesize x = _x;` by saying `@synthesize x;` you are really saying `@synthesize x = x;` Does that make sense? — Justin Meiners, May 12 '13 at 16:32
@DrummerB not that one, but im sure this question has been asked — Justin Meiners, May 12 '13 at 16:32
I explained all this in my answer to that question, that's why I linked it. — DrummerB, May 12 '13 at 16:35

score 1 · Accepted Answer · answered May 12 '13 at 16:35

1

If you write @synthesize x; you can either use self.x or x

If you don't synthesize the property the compiler does behind the scenes this: @synthesize x = _x. Now you can either use self.x or _x

But you can synthesize and assign the ivar a different name as well, e.g. @sythesize x = _aBoolen —now you can use self.x or _aBoolean

answered May 12 '13 at 16:35

JDS

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Note that `self.x` and `_x` as accessors or setters are quite different in behavior; the former is a KV observable method call, the latter is not. – bbum May 12 '13 at 17:32

private property in objective c

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