iOS Interview Questions and Answers

There are CPU designs upheld by IOS gadgets:-

iPhones and Ipads

• Arm64 is the current 64-bit ARM CPU design, as utilized since the iPhone 5S and later (6, 6S, SE and 7), the iPad Air, Air 2 and Pro, with the A7 and afterward chips.
• armv7s (a.k.a. swift, not to be confused with the language of a similar name), is utilized in Apple's A6 and A6X chips on iPhone 5, iPhone 5C and iPad 4.
• armv7, a first variation of the 32-bit ARM CPU, as utilized in the A5 and prior.

TvOS

• On tvOS, Elements underpins three structures for gadget sending:
• arm64 is the current 64-bit ARM CPU design and utilized on Apple TV 4
• x64_64 (i.e., 64-bit Intel) is utilized in the Simulator

WatchOS

• On tvOS, Elements underpins three designs for gadget arrangement:
• Armv7k is a 32-bit variation of standard armv7 and utilized on Apple Watch Series 0, 1 and 2.
• i386 (i.e., 32-bit Intel) is utilized in the Simulator

ARC is an IOS 5 specific feature and using storyboard means that you need to raise minimum supported OS to IOS 5.

We cannot support the same application for iPhone 3GS AND 5, 6, 7 because iPhone 3GS doesn’t support IOS6 or later versions.

The easiest solution is to inform Xcode to compile everything as Objective C++ merely. Set your target on the settings to Compile Sources As to Objective C++ and recompile. After that use C++ or Objective C anywhere you want.

you can create .app, .ipa, .a and .framework.

NO, You can’t offer something aside from code with a static library. This is often as a result of .a files measure an accessible archive of object files, with the extra ability beneath Mac/iOS of supporting multiple processor architectures.

The responder chain is a series of coupled responder objects. It starts with the primary responder and finishes with the app object. If the primary responder cannot handle an occurrence, it forwards the event to consecutive responder within the responder chain.

NSObject -> UIResponder ->UIView -> UiControl ->UIButton.

You can additionally produce a custom read to encapsulate the visual appearance and behavior of your own reusable element. For instance, in a very news reading application, we would desire a standard part to show pictures with a caption employing a consistent style on each the home page view controller similarly individual story view controller.

An app in iOS goes through completely different states as it runs. These shows the states of the appliance life cycle. Below are the states of the associate app.

• Not running

The application has not been running or was launched however was terminated by the system.

• Inactive

The app is running within the foreground; however, it is presently not receiving events. (It is also death penalty alternative code though) the associate app typically stays during this state because it transitions to a distinct state.

• Active

The app is running within the foreground and is receiving events. This is often the conventional mode for foreground apps.

• Background

The app is within the context and executing code. Most apps enter this state shortly on their way to being suspended. However, an associate app that requests additional execution time might stay during this state for an amount of your time. Additionally, an app being launched directly into the background enters this state rather than the inactive state. For info concerning the way to execute code whereas within the environment, see Background Execution.

• Suspended

The app is within the background; however, executing code isn’t. The system moves apps to the current state mechanically and doesn't send word them before doing this. Whereas suspended, the associate app remains in memory however doesn't execute any code.