Tuples

Basics

• Tuples Type Provide way to group multiple Data elements into light weight structure
• Tuples are very usefull as method return type, when you need to return multiple value instead of one
• Tuples can also implemented as replacement for light classes to reduce code clutter and simplicity
• One of my favorite use case is storing Tabular data using List of Tuple with Field Names. for Example storing List of books, with each book having Unique ID, Name, no of pages, Author... etc

Example Tuples without Field names

(int, string, int) Book;

Book.Item1 = 1;
Book.Item2 = "The Way of Kings";
Book.Item3 = 1200;

Console.WriteLine($"{Book.Item1}-{Book.Item2}-{Book.Item3}");

Example Tuple with Field Names

(int Id, string Name,int Pages) Book=(1,"The Way of King",1200);

Console.WriteLine($"{Book.Id}-{Book.Name}-{Book.Pages}");

(int Id, string Name, int Pages) Book;

Book.Id = 1;
Book.Name = "The Way of Kings";
Book.Pages = 1200;

Console.WriteLine($"{Book.Id}-{Book.Name}-{Book.Pages}");

var sum = 4.5;
var count = 3;
var t = (sum, count);
Console.WriteLine($"Sum of {t.count} elements is {t.sum}.");

var a = 1;
var t = (a, b: 2, 3);
Console.WriteLine($"The 1st element is {t.Item1} (same as {t.a}).");
Console.WriteLine($"The 2nd element is {t.Item2} (same as {t.b}).");
Console.WriteLine($"The 3rd element is {t.Item3}.");
// Output:
// The 1st element is 1 (same as 1).
// The 2nd element is 2 (same as 2).
// The 3rd element is 3.

Example: Method with Tuple Return

var xs = new[] { 4, 7, 9 };
var limits = FindMinMax(xs);
Console.WriteLine($"Limits of [{string.Join(" ", xs)}] are {limits.min} and {limits.max}");
// Output:
// Limits of [4 7 9] are 4 and 9

var ys = new[] { -9, 0, 67, 100 };
var (minimum, maximum) = FindMinMax(ys);
Console.WriteLine($"Limits of [{string.Join(" ", ys)}] are {minimum} and {maximum}");
// Output:
// Limits of [-9 0 67 100] are -9 and 100

(int min, int max) FindMinMax(int[] input)
{
    if (input is null || input.Length == 0)
    {
        throw new ArgumentException("Cannot find minimum and maximum of a null or empty array.");
    }

    var min = int.MaxValue;
    var max = int.MinValue;
    foreach (var i in input)
    {
        if (i < min)
        {
            min = i;
        }
        if (i > max)
        {
            max = i;
        }
    }
    return (min, max);
}

Work with List of Tuples

(int Id, string Name, int Pages) Book1 = (1, "The Way of King", 1200);
(int Id, string Name, int Pages) Book2 = (2, "Words of Radiance", 1100);

var books = new List<(int Id, string Name, int Pages)>();
books.Add(Book1);
books.Add(Book2);
books.Add((3,"Oathbringer",1000));

//Loop through list of tuple
for (int i = 0; i < books.Count; i++)
{
    Console.WriteLine($"{books[i].Id}-{books[i].Name}-{books[i].Pages}");
}

//Loop using for each
foreach (var book in books)
{
    Console.WriteLine($"{book.Id}-{book.Name}-{book.Pages}");
}