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iOS Build a Simple iPhone App with Objective-C Creating a Data Model Creating a Data Collection

Posted by Karan Khare
Karan Khare
3,477 Points

Data collection

Can we create NSArray and NSDictionary in .h file if we want to give global access. and if we are declaring these data collection in .m file then why we are doing it in under Particular method.

1 Answer

landonferrier
landonferrier
25,097 Points

Karan, you have a very good questions. In most cases, dictionaries and arrays aren't used for global access, they are used to complete tasks within methods that are only stored within that method.

Here is an example:

-(float)addNumbersWithNumberOne:(float)numberOne numberTwo:(float)numberTwo {


    float answer = numberOne + numberTwo;

    return answer;
}

func addNumbers (numberOne: Float, numberTwo: Float) -> Float {

   var answer: Float = numberOne + numberTwo;

   return answer;
}

In the above examples, there is a data type, the answer, stored inside of the method to hold the sum of the two numbers. Since the methods caller of sender just cares about the return value, the answer float is completely irrelevant. As long as the code works, a programmer will not need to know the inner workings of a method.

If you have any questions, feel free to ask!