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Swift Tuples
A tuple in Swift is a constant or variable that can hold a group of values, which can be of different data types, combined into a single value. In simpler terms, a tuple is a structure that allows multiple values of various types to be stored together. Tuples are often used as return values to retrieve multiple data points from a function or process.
Creating a Tuple in Swift
To create a tuple, declare a constant or variable and define the data inside parentheses () separated by commas. The elements can be of the same or distinct data types.
Example 1: Declaring a Tuple Containing a String and an Integer
// statusLoad is of type (String, Int) and equals (“Forbidden”, 403)
let statusLoad = ("Forbidden", 403)
Here, the tuple statusLoad holds two values:
- A
Stringproviding a human-readable description ("Forbidden") - An
Intrepresenting a numeric code (403)
Example 2: Declaring Tuples with Multiple Data Types
let a = (1, 2, 3, 4)
var b = ("Hello", 42, "Swift", 7, 99)
Tuples can also have named elements for better readability.
Example 3: Naming Elements Inside a Tuple
let statusLoad = (tupleMessage: "Forbidden", tupleCode: 403)
Decomposing a Tuple
You can access tuple elements by decomposing the tuple into variables or constants, as shown below:
// Refer to statusLoad from above
let (sMessage, sCode) = statusLoad
// Print the message
print("The status message is \(sMessage).")
// Print the code
print("The status code is \(sCode).")
Output:
The status message is Forbidden.
The status code is 403.
Example 4: Accessing Tuple Elements Using Indexes
You can access elements in a tuple using their index.
let person = ("John", 25, "Developer")
// Accessing elements by index
print("Name: \(person.0)")
print("Age: \(person.1)")
print("Profession: \(person.2)")
Output:
Name: John
Age: 25
Profession: Developer
Example 5: Naming Tuple Elements and Accessing Them
Named elements make accessing tuple values more intuitive.
let book = (title: "Swift Programming", author: "John Doe", pages: 350)
// Accessing elements by name
print("Book Title: \(book.title)")
print("Author: \(book.author)")
print("Number of Pages: \(book.pages)")
Output:
Book Title: Swift Programming
Author: John Doe
Number of Pages: 350
Example 6: Returning a Tuple from a Function
Tuples are commonly used as return types for functions when you want to return multiple values.
func getDeviceInfo() -> (name: String, price: Double, inStock: Bool) {
return ("iPhone", 999.99, true)
}
let device = getDeviceInfo()
print("Device Name: \(device.name)")
print("Price: \(device.price)")
print("In Stock: \(device.inStock)")
Output:
myArray: ["Swift", "iOS", "Xcode", "iPad"]
Example 7: Using a Tuple in a For Loop
You can use tuples to iterate over key-value pairs in a collection.
let scores = [("Alice", 90), ("Bob", 85), ("Charlie", 95)]
for (name, score) in scores {
print("\(name) scored \(score) marks.")
}
Output:
Alice scored 90 marks.
Bob scored 85 marks.
Charlie scored 95 marks.