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Mike Lange
794 PointsWhy can you set "author" variable under "bp", when in "bp" we have only called the "title" property?
Not really understanding why when we define the "bp" variable that calls the title property that we can define also the author variable, when in blogposts under the title method we have no definition or call to the "author" property....
eg.
BlogPost *blogPost = [[BlogPost alloc] initWithTitle:@"Dummy Title"];
blogPost.author = @"hello";
- blogPost allocated and initialised title method.
- blogPost can now see and set "author" property - how?
Is someone able to explain this?
Is this simply a case that if you initialise any variable under the class (ie. "*blogPost" above) that this variable can then also set and define any other property defined within the same class file (ie. "BlogPost" class) via "{variable}.{propertytitle}" eg. "blogPost.author".
1 Answer
Tim Luk
5,140 PointsInitializing something means setting a initial value. Designated initializer means these value( in this case - author) must be when initializing it. You can also pass a another augment for the title if you want, so when you initialize it, you will need both the title and the author. In our case, it's optional to add a author.
The reason why you can do all this is because, at the header file you added the line - (blogPost ) initWithTitle: NSString title; -(id) is the return type, which consists of 2 instance variable. The compiler knows there are 2 instance variable, because it's in the same class.