Constant vs Variable vs Literal

Literal ->It means “A literal is some data that’s presented directly in the code, rather than indirectly through a variable or function call.” The term “literal” comes from the fact that you’ve written data literally into your program, i.e. exactly as written, not “hidden” behind a variable name (i.e representing a fixed value in source […]


UIResponder An abstract interface for responding to and handling events. Users manipulate their iOS devices in a number of ways, such as touching the screen or shaking the device. iOS interprets when and how a user is manipulating the hardware and passes this information to your app. Overview Responder objects—that is, instances of UIResponder—constitute the […]

iOS App Architecture

Q) What is Architecture? Architecting is nothing but organizing all, the independently working, layers in a best way that suits your project. There is no one fixed architecture that suits well for all the projects all the time. Each projects could have an unique approach. Now that being said, it would introduce two questions to you, What […]

What is MVVM?

Q) What is MVC? Ans: It’s a design pattern and a standard approach to build iOS apps.  In this design pattern, the controller separates the model from the view so that each can change independently. If we didn’t have such a decoupling then every time the model changed, the view would need to change as well. […]

Difference between cocoa and cocoa touch

Cocoa is commonly referred to as the combination of the Foundation and AppKit frameworks, while Cocoa Touch is the combination of the Foundation and UIKit frameworks. Cocoa and Cocoa Touch sit on top of other collections of frameworks to create the API stacks. The other layers are Media, Core Services and Core OS. The big […]