[Objective-C] Access Modifiers

 Access Modifiers

Objective-C also provides 3 access modifiers for member variables:

• @public: no access restrictions
• @private: accessible within the defining class
• @protected: accessible within the defining class and by derived classes (default)

• The default access mode is “protected“
• Access modifiers can be applied only to member variables; methods are always public.

Note that the member variables are located in the “{ }” section.

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/* Product.h */ @interface Product : NSObject {   @private     int productId;   @public     NSString *productName;     float price; } -(void) setProductId: (int) n; -(int) getProductId; @end

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/* Product.m */ #import #import "Product.h" @implementation Product -(void) setProductId: (int) n {   productId = n; } -(void) getProductId {   return productId; } @end

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/* MainApp.m */ #import #import "Product.h" int Test() {   Product *p = [Product new];   [p setProductId:100];   p->productName = @"Toy";   p->price = 9.99;   NSLog(@"Id: %d", [p getProductId]);   NSLog(@"Name: %@", p->productName);   NSLog(@"Id: %4.2f", p->price); } ...