CODEWITHSUNDEEP
iosobjective-c
ios
ios

Reputation: 165

What is the recommended way to access instance variables and methods?

ViewController.h

@property (strong,nonatomic) NSMutableArray *products;

@property (strong, nonatomic) IBOutlet UITableView *tableViewProducts;

i would like to know apple or developer recommended method of accessing instance variables and accessor methods.

Should i use _instanceVariable or self.instanceVariable or should i synthesize all ivars ?

Method 1

ViewController.m

@synthesize products;
@synthesize tableViewProducts;
@synthesize productCount;
......
UITableViewCell *cell=[tableViewProducts dequeueReusableCellWithIdentifier:@"cellReuseIdentifier"];
productCount.

Method 2

ViewController.m

UITableViewCell *cell=[_tableViewProducts dequeueReusableCellWithIdentifier:@"cellReuseIdentifier"];

Method 3

ViewController.m

UITableViewCell *cell=[self.tableViewProducts dequeueReusableCellWithIdentifier:@"cellReuseIdentifier"];

Upvotes: 0

Views: 78

Answers (4)

Lal Krishna
Lal Krishna

Reputation: 16170

You doesn't need to @synthesize all properties. But Can @synthesize property to create custom Setter Method.

self.propertyName will trigger this setter Method & _propertyName won't trigger.

Example:

.h

@property(string, nonatomic) NSString *name;

.m

@synthesize name = _name;
- (void)setName:(NSString *)name {
    _name = name;
}

Upvotes: 0

Dave Wood
Dave Wood

Reputation: 13333

Always access properties with the accessor methods, so always use self.property etc. Except, in init (and initWithWhatever etc) methods, in which you should always access the backing variable directly _property etc. This is to avoid side effects of accessing self before self has finished initializing.

The reason you always want to use self.property is because that enables useful side effects. The accessor methods can be overridden to validate values, trigger KVO effects (automatically update views for example), use default values if no specific value has been set and much more. Those are bypassed if you use the backing variables directly.

Upvotes: 2

thxou
thxou

Reputation: 691

Nowadays you don't need to @synthesize properties. Since you've already defined your properties you even don't need to user the instance variable, simple use the property itself as self.instanceVariable.

Upvotes: 0

rmaddy
rmaddy

Reputation: 318824

You haven't needed to use @synthesize for years now so don't bother adding those lines.

Since you have properties, access the properties, not the underlying instance variables.

This means your 3rd option is the best choice.

Upvotes: 2

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