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How do I call Objective-C code from Swift? - Stack Overflow
Apr 14, 2024 · To import a set of Objective-C files into Swift code within the same app target, you rely on an Objective-C bridging header file to expose those files to Swift. Xcode offers to create this header when you add a Swift file to an existing Objective-C app, or an Objective-C file to an existing Swift app.
#ifdef replacement in the Swift language - Stack Overflow
Aug 13, 2021 · In Swift you can still use the "#if/#else/#endif" preprocessor macros (although more constrained), as per Apple docs. Here's an example: #if DEBUG let a = 2 #else let a = 3 #endif Now, you must set the "DEBUG" symbol elsewhere, though. Set it in the "Swift Compiler - Custom Flags" section, "Other Swift Flags" line.
Simplest way to throw an error/exception with a custom message …
@VyachaslavGerchicov If you don’t know a simpler way for Swift, which was also specified in the question, then this would be the simplest way, even of you don’t consider it simple in a more general context that would include Objective-C. (Also, this answer is basically a one-line one-time definition of an enum, the function and its call is ...
ios - How to create a delay in Swift? - Stack Overflow
Dec 17, 2014 · In Swift 4.2 and Xcode 10.1. You have 4 ways total to delay. Out of these option 1 is preferable to call or execute a function after some time.
How to call C from Swift? - Stack Overflow
May 17, 2015 · To use C++ files directly, you should create an objective-C wrapper. You'll want the implementation (which should reside by itself in a .mm file) to contain Objective-C++ code (which is just Objective-C and C++ in one file), and the interface (which should be in its own .h header file) should contain pure Objective-C code, so you'll have to convert C++ types to …
What is the difference between `let` and `var` in Swift?
Jun 3, 2014 · Swift let vs var. let - constant var - variable [Constant vs variable] [Struct vs Class] Official doc docs.swift.org says. The value of a constant can’t be changed once it’s set, whereas a variable can be set to a different value in the future. This terminology actually describes a reassign mechanism. Mutability
swift - What does the SwiftUI `@State` keyword do? - Stack Overflow
Jun 4, 2019 · The @State keyword is a @propertyWrapper, a feature just recently introduced in Swift 5.1. As explained in the corresponding proposal , it's sort of a value wrapper avoiding boilerplate code. Sidenote: @propertyWrapper has previously been called @propertyDelegate , but that has changed since.
Split a String into an array in Swift? - Stack Overflow
Split is a native Swift method introduced in Swift 4, and it returns an array of Substring values. On the other hand, components are part of the NSString class and return an array of String values. If you need the result as String values and are working with native Swift types, split is …
How do I concatenate strings in Swift? - Stack Overflow
Jun 4, 2014 · How to concatenate string in Swift? In Objective-C we do like. NSString *string = @"Swift"; NSString *resultStr = [string stringByAppendingString:@" is a new Programming Language"]; or. NSString *resultStr=[NSString stringWithFormat:@"%@ is a new Programming Language",string]; But I want to do this in Swift-language.
Add an element to an array in Swift - Stack Overflow
Swift 4.2 var myArray: NSArray = [] let firstElement: String = "First element" let secondElement: String = "Second element" // Process to add the elements to the array myArray.adding(firstElement) myArray.adding(secondElement)