Swift

A collection of 39 posts

Swift

Nested class in Swift

A nested class in Swift is a class that is defined within another class. Some key features: * Nested class have access to local variables or constants of the outer class unless these variables or constants are marked as static. * Nested class can be marked as private, fileprivate, or internal. Here

RxSwift

2 hours to master RxSwift - Part 2

In this article we will dig a bit more depth in some core concepts on 2 hours to master RxSwift - Part 1. Section 1: Observable Like mentioned in the last article, an Observable in RxSwift will emit events (values and errors) over time, and notifies its observers, and nearly

RxSwift

2 hours to master RxSwift - Part 3

Introduction In the previous post: 2 hours to master RxSwift - Part 1 (needone.app) and 2 hours to master RxSwift - Part 2 (needone.app), we get to know the the core concept behind the RxSwift and how RxSwift works. In this tutorial, we are going to combine what

Swift Featured

2 hours to master RxSwift - Part 1

a simple introudction on rxswift, including what is rxswift, how to use it and a quick example (with swift code) on demo that.

Swift

Generic type vs. Any in Swift

Generic type In Swift, a generic type is a placeholder for a specific type that is specified when the generic type is used. A generic type allows you to write flexible and reusable code that can work with any type, while still taking advantage of type safety. For example, you

iOS

indirect enum in Swift

An indirect enum in Swift is an enum that can be used to define a recursive data structure. This means that one or more of its cases can refer to an instance of the same enum type. Here is an example of an indirect enum in Swift: indirect enum TreeNode&

Swift

UITraitCollection

UITraitCollection is a class in the UIKit framework that defines a set of interface traits that specify the environment in which your app is running. These traits include the device’s display scale, user interface style, and size class. You can use the information contained in a UITraitCollection object to

Swift

UIKit vs. SwiftUI - A general discussion

UIKit and SwiftUI are two different frameworks for building user interfaces on Apple platforms. UIKit UIKit is the older of the two frameworks, and has been around since the early days of iOS development. It is a mature and powerful framework that provides a wide range of tools and APIs

Swift

Sort custom objects by property in Swift

Many of us have met the situation that we have an array/list of custom objects, and we want them can be sorted in a specific order. For example, we are have a group of people, and we want to sort the whole array by the person's age.

Swift

Format currency in Swift

Recently I have done quite an amount of work on formatting currency in Swift project, here are some tricks on how to format number in Swift: Format currency with auto  currency symbol By using the NumberFormatter class, we can convert numbers into string(s), and vice versa. More conveniently, we

iOS

Get the current week in Swift

To get the current week in Swift 5, you can use the Calendar and DateComponents classes to calculate the week number for the current date. Here's an example of how you might do this: let calendar = Calendar.current let currentDate = Date() let currentWeek = calendar.component(.weekOfYear, from: currentDate)

iOS

SceneDelegate

In iOS, the SceneDelegate is a class that is responsible for managing the scenes in your app. A scene is a discrete unit of your app's user interface, such as a window or tab. The SceneDelegate class provides methods that are called at various points in the lifecycle

Swift

Data Racing in Swift

A data race in Swift occurs when two or more threads access the same memory location simultaneously and at least one of them is writing to it, without proper synchronization. This can lead to unexpected behavior or crashes in your program. In Swift, there are two common scenarios on data

Swift

Get location coordinates using CLLocationManager in Swift

To get the location (latitude and longitude) of a device in Swift, you can use the Core Location framework, which is an official library from Apple. Only 2 steps are required, so it is pretty simple: Step 1: Set up proper permission To get the location of a device in

Swift

Encode URL in Swift

It is quite common to see that we can correctly set up the HTTP header, token, body and POST/GET methods in our iOS code, but we still can't get the right response. Here is an error which most of people encounter before, incorrect url encoding. Sometimes the

Swift

Nested method in Swift

A nested method in Swift is a method or function that is defined within another function. Nested functions have the following characteristics: * They have access to all variables and constants of the outer function, including local variables and parameters. * They do not have access to variables or constants in the

iOS

Popup alert in Swift

As mentioned in the other article: Popup Custom View in UIKit: popup mainly can be: * popup an alert using UIAlertController * popup action sheet using UIAlertController. For more details, check this: Present action sheet in UIKit and SwiftUI * popup a custom view/viewController A popup dialog is a component that displays

Swift

Popup Custom View in UIKit

In UIKit, popup mainly can be: * popup an alert using UIAlertController * popup action sheet using UIAlertController. For more details, check this: Present action sheet in UIKit and SwiftUI * popup a custom view/viewController The following will demonstrate how to present a custom view/viewController by  creating a custom popup by

iOS

Compiler directives in Swift

This post is going to list some of the most frequently used compiler directives in Swift, compatible in Swift 3/4/5. Someone might call this preprocessor directives, but they are the same concept. In this post, we list few commonly used directives with detailed examples: Updated in 2022 #sourceLocation

Swift

Present action sheet in UIKit and SwiftUI

An action sheet is a component that displays a set of choices to the user in a modal format. UIKit In iOS, you can create an action sheet using a UIAlertController with the .actionSheet style. Here is an example of how to create an action sheet in Swift: let actionSheet

Swift

What is keyword defer in Swift

The defer keyword in Swift is used to execute a block of code at the end of the current scope, regardless of how the scope is exited. The defer block is executed after any return statements, and before any finally blocks. Here is an typical example of how to use

iOS

Command pattern in Swift

Many of us have heard about the Command pattern or used them in the development, which is a behavioral design pattern in which an object is used to encapsulate all of the information required to perform an action or trigger an event at a later time. This information includes, for

Swift

Have you tried XCTUnwrap before?

What is XCTUnwrap and how to use it to help you effectively while you are doing the unit test? XCTUnwrap is a utility function that is used in unit tests to unwrap optional values. It is part of the XCTest framework, which is the default testing framework for iOS and

Swift

PLIST file in iOS

A Property List (PLIST) file is a file format used by macOS and iOS to store serialized data. It is often used to store data such as user preferences, settings, and other information that needs to be stored persistently. PLIST files can either be stored in a binary format and

Swift

Create Property Wrapper in Swift

What is Property Wrapper Property wrapper are a language feature that allows you to wrap a piece of code around a property in Swift world, which can help us to add additional behavior or functionality to that property. The benefits of it is to reduce the code repetition. Property wrapper