iOS 面试题与答案

问题 21. Which is the application thread from where UIKit classes should be used?

Unless it’s stated, use UIKit classes only from your application’s main thread or main dispatch queue. This restriction applies in particular to classes derived from UIResponder or that require modifying the user interface of your app in some way.

问题 22. What is the difference between Synchronous & Asynchronous tasks?

• Synchronous can also be defined as In order. When you perform the synchronous operation, all that follows must wait for the operation to complete before proceeding.
• In contrast, “asynchronous” can also be defined as “out of order.” When you do something asynchronously, you can run the following code right away, and the asynchronous process will happen someday. It could be run on a separate thread from the rest of the code. It could easily be rescheduled on the same thread at a later date and you can notify you when it is done.

问题 23. What is Operator Overloading?

The process of adding new operators and changing existing ones to do various things is known as operator overloading.

+, *, and / symbols are known as operators.

问题 24. What is TVMLKit?

TVMLKit serves as a bridge between TVML, JavaScript, and your native tvOS software. You can test TVMLKit JS and TVML files from inside your tvOS app using the TVMLKit framework. The JavaScript environment can be used to build TVML objects, styles, views, and view controllers.

问题 25. What are UI Elements in iOS?

The visual elements that we can see in our applications are known as UI elements. Some of these components, such as buttons and text fields, respond to user interactions, while others, such as images and labels, provide information.