swift Archives - Page 5 of 8

Determining if Swift dictionary contains key and obtaining any of its values

I am currently using the following (clumsy) pieces of code for determining if a (non-empty) Swift dictionary contains a given key and for ...

May 15, 2022
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Difference between == and ===

In swift there seem to be two equality operators: the double equals (==) and the triple equals (===), what is the difference between ...

May 14, 2022
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How can I use String substring in Swift 4? ‘substring(to:)’ is deprecated: Please use String slicing subscript with a ‘partial range from’ operator

I have the following simple code written in Swift 3: let str = "Hello, playground" let index = str.index(of: ",")! let newStr = ...

May 13, 2022
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Read and write a String from text file

I need to read and write data to/from a text file, but I haven’t been able to figure out how. I found this ...

May 13, 2022
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What is the difference between `let` and `var` in Swift?

What is the difference between let and var in Apple’s Swift language? In my understanding, it is a compiled language but it does ...

May 11, 2022
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How do I print the type or class of a variable in Swift?

Is there a way to print the runtime type of a variable in swift? For example: var now = NSDate() var soon = ...

May 11, 2022
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What is the “some” keyword in Swift(UI)?

The new SwiftUI tutorial has the following code: struct ContentView: View { var body: some View { Text("Hello World") } } The second ...

May 11, 2022
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What is the ‘open’ keyword in Swift?

The ObjectiveC.swift file from the standard library contains the following few lines of code around line 228: extension NSObject : Equatable, Hashable { ...

May 10, 2022
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Get class name of object as string in Swift

Getting the classname of an object as String using: object_getClassName(myViewController) returns something like this: _TtC5AppName22CalendarViewController I am looking for the pure version: "CalendarViewController". ...

May 9, 2022
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Precision String Format Specifier In Swift

Below is how I would have previously truncated a float to two decimal places NSLog(@" %.02f %.02f %.02f", r, g, b); I checked ...

May 6, 2022
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