21⟩ Explain me what Is A Deinitializer In Swift?
If you want to perform an additional clean-up of your classes, it is possible to define a block called deinit.
Syntax -
deinit {
//Your cleanup statement here.
}
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“Swift Developer based Frequently Asked Questions in various Swift Developer job interviews by interviewer. These professional questions are here to ensures that you offer a perfect answers posed to you. So get preparation for your new job hunting”
39 Swift Developer Questions And Answers
22⟩ Tell us how can you define a base class in swift?
The classes are not inherited directly from the base class in the Swift programming language.The classes defined by the developer without specifying the superclass becomes the base class automatically.
23⟩ Can you explain Functions?
It lets you group a series altogether to perform a specific task.A function once created can be over and over in the code, and in case you find a repeating statement in the code, then the function can be the answer to avoid the repetition.
24⟩ Tell us what Lazy stored properties are and when they are useful?
Lazy stored properties are used for a property whose initial values are not set until the first time it is used . You can declare a lazy stored stored property by writing the lazy modifier before its declaration. Lazy properties are useful when the initial value of a property is reliant on outside factors whose values are unknown.
25⟩ How to write a multiple line command Swift?
The multiple line comment is written in between the symbols (/*) at the start and (*/) at the end.
26⟩ Tell me how can you make a property optional in Swift?
Declaring a question mark “?” in the code can make a property optional.
If a property doesn’t hold a value, then this symbol “?” helps in avoiding the runtime errors.
27⟩ Do you know what is the reuseIdentifier used for?
The reuseIdentifier is used to indicate that a cell can be re-used in a UITableView. For example when the cell looks the same, but has different content. The UITableView will maintain an internal cache of UITableViewCell’s with the reuseIdentifier and allow them to be re-used when dequeueReusableCellWithIdentifier: is called. By re-using table cell’s the scroll performance of the tableview is better because new views do not need to be created.
28⟩ Tell me the features of Swift Programming?
► Variables are always initialized before use.
► Memory is managed automatically.
► Arrays and integers are checked for overflow.
► Switch function can be used instead of using “if” statement.
► It eliminates the classes that are in unsafe mode.
29⟩ What is the difference between atomic and nonatomic synthesized properties?
Atomic and non-atomic refers to whether the setters/getters for a property will atomically read and write values to the property. When the atomic keyword is used on a property, any access to it will be “synchronized”. Therefore a call to the getter will be guaranteed to return a valid value, however this does come with a small performance penalty. Hence in some situations nonatomic is used to provide faster access to a property, but there is a chance of a race condition causing the property to be nil under rare circumstances (when a value is being set from another thread and the old value was released from memory but the new value hasn’t yet been fully assigned to the location in memory for the property).
30⟩ Tell us any three-shift pattern matching techniques?
☛ Typecasting Patterns – This pattern allows you to match or cast the types.
☛ Wildcard Patterns – This pattern matches as well as ignores any kind and type of value.
☛ Optional Patterns – This pattern is used to match the optional values.
31⟩ Tell us what Are The Control Transfer Statements In Swift?
The control transfer statements in swift are:
☛ Continue
☛ Break
☛ Fallthrough
☛ Return
32⟩ Explain me what Is Swift Programming Language?
Swift is an innovative new programming language for Cocoa and Cocoa Touch. Writing code is interactive and fun, the syntax is concise yet expressive, and apps run lightning-fast. Swift is ready for your next iOS and OS X project — or for addition into your current app — because Swift code works side-by-side with Objective-C.
33⟩ Tell me what Is Dictionary In Swift?
It enables you to store the key-value pairs and access the value by providing the key.It is similar to that of the hash tables in other programming languages.
34⟩ Please explain some common execution states in iOS?
The states of the common execution can be as follows:
☛ Not running – This state means that there is no code that is being executed and the application is completely switched off.
☛ Inactive – This state means that the application is running in the background and is not receiving any events.
☛ Active – This state means that the applications are running in the background and is receiving the events.
☛ Background – This state means that the application is executing the code in the background.
☛ Suspended – This state means that the application is in the background and is not executing.
35⟩ Explain how Can You Define A Base Class In Swift?
The classes are not inherited directly from the base class in the Swift programming language.The classes defined by the developer without specifying the superclass becomes the base class automatically.
36⟩ What is completion handler?
When our application is making an API call and we are supposed to update the UI to show the data from the API call, then Completion Handler becomes handy and is super convenient.
37⟩ Explain me what is a category and when is it used?
A category is a way of adding additional methods to a class without extending it. It is often used to add a collection of related methods. A common use case is to add additional methods to built in classes in the Cocoa frameworks. For example adding async download methods to the UIImage class.
38⟩ Please explain regular expression and Responder chain?
Regular Expression – These are the special string patterns that describe how a search is performed through a string.
Responder Chain – It is a hierarchy of objects that obtain the opportunity to respond to the events.
39⟩ Tell me regular Expression And Responder Chain?
Regular Expression – These are the special string patterns that describe how a search is performed through a string.
Responder Chain – It is a hierarchy of objects that obtain the opportunity to respond to the events.
