Here’s a list of 50 Swift interview questions and answers. These questions focus on Swift programming and iOS app development. You need to know the answers to these before you get a chance to show your skills in front of a job interviewer.
What is trailing closure syntax?[/vc_column_text][/vc_column][/vc_row][vc_row type=”in_container” full_screen_row_position=”middle” equal_height=”yes” content_placement=”middle” scene_position=”center” text_color=”dark” text_align=”left” top_padding=”10″ bottom_padding=”10″ overlay_strength=”0.3″ shape_divider_position=”bottom” bg_image_animation=”none” shape_type=””][vc_column column_padding=”no-extra-padding” column_padding_position=”all” background_color_opacity=”1″ background_hover_color_opacity=”1″ column_link_target=”_self” column_shadow=”none” column_border_radius=”none” width=”1/1″ tablet_width_inherit=”default” tablet_text_alignment=”default” phone_text_alignment=”default” column_border_width=”none” column_border_style=”solid” bg_image_animation=”none”][vc_column_text]The trailing closure syntax is a little bit of syntactic sugar that makes reading and writing, particularly common code, more enjoyable. Many functions in iOS accept multiple parameters, with the last parameter being a closure.
If the last parameter of a function is a closure, Swift allows you to use a special syntax called trailing closure syntax. Instead of passing your closure as a parameter, you pass it directly after the parenthesized function.[/vc_column_text][/vc_column][/vc_row][vc_row type=”in_container” full_screen_row_position=”middle” scene_position=”center” text_color=”dark” text_align=”left” top_padding=”10″ bottom_padding=”10″ overlay_strength=”0.3″ shape_divider_position=”bottom” bg__animation=”none” shape_type=””][vc_column column_padding=”no-extra-padding” column_padding_position=”all” background_color_opacity=”1″ background_hover_color_opacity=”1″ column_link_target=”_self” column_shadow=”none” column_border_radius=”none” width=”1/1″ tablet_width_inherit=”default” tablet_text_alignment=”default” phone_text_alignment=”default” column_border_width=”none” column_border_style=”solid” bg__animation=”none”][vc_column_text]
What is a good use case for an inout parameter?[/vc_column_text][/vc_column][/vc_row][vc_row type=”in_container” full_screen_row_position=”middle” scene_position=”center” text_color=”dark” text_align=”left” overlay_strength=”0.3″ shape_divider_position=”bottom” bg_image_animation=”none”][vc_column column_padding=”no-extra-padding” column_padding_position=”all” background_color_opacity=”1″ background_hover_color_opacity=”1″ column_link_target=”_self” column_shadow=”none” column_border_radius=”none” width=”1/1″ tablet_width_inherit=”default” tablet_text_alignment=”default” phone_text_alignment=”default” column_border_width=”none” column_border_style=”solid” bg_image_animation=”none”][vc_column_text]inout means that changing the local variable will also change the passed parameters. Without it, the passed parameters will remain at the same value. Try thinking of a reference type when using Inout and a value type without it.
1. A good use case would be the swap function, where it will change the passed parameters.
2. Consider removing the overhead of copying as well. If you have a function that takes a somewhat memory-large value type as an argument (e.g., a large struct type) and returns the same type, and finally, the return of the function is always used only to replace the caller argument, then inout as the associated function parameter is preferable.[/vc_column_text][/vc_column][/vc_row][vc_row type=”in_container” full_screen_row_position=”middle” scene_position=”center” text_color=”dark” text_align=”left” top_padding=”10″ bottom_padding=”10″ overlay_strength=”0.3″ shape_divider_position=”bottom” bg__animation=”none” shape_type=””][vc_column column_padding=”no-extra-padding” column_padding_position=”all” background_color_opacity=”1″ background_hover_color_opacity=”1″ column_link_target=”_self” column_shadow=”none” column_border_radius=”none” width=”1/1″ tablet_width_inherit=”default” tablet_text_alignment=”default” phone_text_alignment=”default” column_border_width=”none” column_border_style=”solid” bg__animation=”none”][vc_column_text]
1 How Can You Improve Code Readability
In our company, we have 20 developers and 20 unique coding styles. How might we enforce some common coding styles/best practices?
What are the common factors between struct and class?[/vc_column_text][/vc_column][/vc_row][vc_row type=”in_container” full_screen_row_position=”middle” equal_height=”yes” content_placement=”middle” scene_position=”center” text_color=”dark” text_align=”left” top_padding=”10″ bottom_padding=”10″ overlay_strength=”0.3″ shape_divider_position=”bottom” bg_image_animation=”none” shape_type=””][vc_column column_padding=”no-extra-padding” column_padding_position=”all” background_color_opacity=”1″ background_hover_color_opacity=”1″ column_link_target=”_self” column_shadow=”none” column_border_radius=”none” width=”1/1″ tablet_width_inherit=”default” tablet_text_alignment=”default” phone_text_alignment=”default” column_border_width=”none” column_border_style=”solid” bg_image_animation=”none”][vc_column_text]
Struct A struct is similar to a class in definition and instantiation. We define a struct using the struct keyword.[/vc_column_text][/vc_column][/vc_row][vc_row type=”in_container” full_screen_row_position=”middle” scene_position=”center” text_color=”dark” text_align=”left” top_padding=”10″ bottom_padding=”10″ overlay_strength=”0.3″ shape_divider_position=”bottom” bg__animation=”none” shape_type=””][vc_column column_padding=”no-extra-padding” column_padding_position=”all” background_color_opacity=”1″ background_hover_color_opacity=”1″ column_link_target=”_self” column_shadow=”none” column_border_radius=”none” width=”1/1″ tablet_width_inherit=”default” tablet_text_alignment=”default” phone_text_alignment=”default” column_border_width=”none” column_border_style=”solid” bg__animation=”none”][vc_column_text]
2 What’s the Difference Between Structures and Classes?
let keywords and attempt to mutate its property, whereas there is no mutability in structures.Optional chaining means you can safely call a property of something that may be nil.
Optional chaining works, as the name suggests, by chaining one or more optional values with a question mark operator ?, like this:
If nil is encountered at any point in the above chain, the app won’t crash — instead, a nil is returned.
Optional binding checks if an optional contains a value or not. If the optional does have a value, optional binding makes that value temporarily available:
As an example, the following code checks if the name is nil or not. If it’s not, a temporary constant realName is created and the value name is assigned to it.
Output:
MVC (Model-View-Controller), is a software architecture for developing iOS apps. It’s one of iOS app development’s fundamental concepts.
Multiple iOS frameworks use the MVC.
The idea of MVC is to pass data from one place to another. It means any object in an falls into one of these three categories: