A tip for optimising speed for your Swift and Objective-C code — Creating a new collection type occupies resources. Frequently creating collection type objects, for example, initialising a dictionary in a for-loop or in a function that is frequently executed, might consume a considerable amount of time. In the following examples, I use reduce(_:_:) and reduce(into:_:) to demonstrate the differences in execution…

About how to create a web view and use JavaScript functions in an iOS project. A quick guide for iOS developers who are not familiar with HTML, JavaScript, and CSS — In my latest iOS project, I needed to calculate something using a JavaScript function. To do this, I called the function through a WKWebView. However, I didn’t actually need a web view displayed on my view. Here’s how to achieve this:

After installing Xcode 15 beta, I encountered error “building for iOS Simulator, but linking in object file built for iOS, file for architecture arm64” — I recently installed Xcode 15 beta 2, and then I noticed that when I tried to run my project on the simulator using Xcode 14.1, I encountered this error: “In …, building for iOS Simulator, but linking in object file built for iOS, file ‘…’ for architecture arm64.”

WWDC 2023 introduced a new UIKit view controller callback: viewIsAppearing. It is the most suitable place to perform tasks that depend on the view’s size or trait collection. Moreover, it can be back-deployed to iOS 13. — iOS UIKit has introduced a new view controller callback called viewIsAppearing, which is called after viewWillAppear but before viewDidAppear. It provides developers with enhanced capabilities to make changes that become visible to the user right from the very first frame of a view controller’s appearance transition. When this callback is…

To free up storage space on your computer, you can consider removing unused simulator runtimes and data. — The size of Xcode is several GB and every iOS developer has to update Xcode every year. If proper storage management is not implemented, your computer’s storage space can quickly become filled to capacity. …

A step-by-step tutorial on how to automate CI pipeline for an iOS app on GitHub — Prerequisites A scheme named CI has been created to define the tests to execute during continuous integration. When changes are merged to master, these tests will be triggered to detect any errors immediately. If you haven’t created one for your continuous integration, please do it first.

A string created from NSLocalizedString is an instance of _NSBPlistMappedString, which might cause an incorrect result of comparing 2 strings — There are 2 strings: one is created from NSLocalizedStringand the other is passed from Swift. The result of comparing if 2 strings are equal is supposed to be YES, but it turns out to be NO. BOOL isEqual = [swiftString isEqualToString: localizedString]; It is because, in iOS 16, a string…

It’s Apple’s design that only when the cell height is equal to or bigger than 90, both image and title will show on the swipe action. There are 3 ways to show both. — The following code sets the action title to “Caught” and sets the image to a system star icon. let starAction = UIContextualAction(style: .normal, title: “Caught”) { _, _, _ in } let starImage = UIImage(systemName: “star.fill”) starAction.image = starImage

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