What are objective categories?

What are objective categories?

Categories provide the ability to add functionality to an object without subclassing or changing the actual object. A handy tool, they are often used to add methods to existing classes, such as NSString or your own custom objects.

What is the use of category in Objective-C?

A category allows you to add methods to an existing class—even to one for which you do not have the source. There is a section in the Objective-C 2.0 programming Language document about Categories and Extensions.

What is objective weighting?

In objective weighting methods, the preferences of decision-makers have no role in determining criteria weights [20]. The objective weighting methods yield criteria weights using a specific computational process based on the initial data or decision-matrix (each alternative’s performance on each criterion).

How do I declare a category in Objective-C?

8 Answers

1. Click File -> New -> File.
2. Select Objective-C file under Sources in iOS or Mac OS respectively and Click Next.
3. Now under File Type: choose either Category , Protocol , or Extension.

What is category in Swift?

In Objective C they were called categories, but in Swift they are called extensions. The purpose of both of them are to give additional functionality to existing classes without having to create subclasses.

What are swift categories?

Categories are a way to modularize a class by spreading its implementation over many files. Extensions provide similar functionality. One of the most common uses of categories is to add methods to built-in data types like NSString or NSArray .

What are the difference between category and extension in Objective-C?

Categories are an Objective-C language feature that let you add new methods to an existing class, much like C# extensions. Objective-C’s extensions are a special case of categories that let you define methods that must be declared in the main implementation block.

What is the purpose of weighting the objectives?

Objective weighting controls the percentage that each objective represents as part of the overall strategy. You can adjust the individual weights for any of the objectives, or you can let PMF automatically balance the weights to give each objective an equal share of the overall strategy.

How do you assign a parameter to a weight?

To calculate how much weight you need, divide the known population percentage by the percent in the sample. For this example: Known population females (51) / Sample Females (41) = 51/41 = 1.24. Known population males (49) / Sample males (59) = 49/59 = .