Deconstruction
Unpack tuples into separate variables.
Deconstruction is a free C# Academy lesson on CoddyKit — lesson 3 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the C# Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
What Is Deconstruction?
Deconstruction splits a tuple (or object) into separate variables in one statement, so you can name each part directly.
using System;
class Program
{
static void Main()
{
var point = (3, 4);
(int x, int y) = point;
Console.WriteLine("x=" + x + ", y=" + y);
}
}Deconstructing a Tuple
Put the target variables in parentheses on the left of =. Each receives the matching tuple element.
using System;
class Program
{
static void Main()
{
var user = ("Ada", 36);
(string name, int age) = user;
Console.WriteLine(name + " is " + age);
}
}Using var in Deconstruction
You can let the compiler infer types with var, either per variable or for the whole group.
using System;
class Program
{
static void Main()
{
var data = (1, "one", true);
var (id, word, flag) = data;
Console.WriteLine(id + " " + word + " " + flag);
}
}Deconstructing a Method Result
You can deconstruct the tuple a method returns directly into named variables.
using System;
class Program
{
static (int, int) MinMax(int a, int b) => a < b ? (a, b) : (b, a);
static void Main()
{
var (lo, hi) = MinMax(8, 3);
Console.WriteLine("min=" + lo + ", max=" + hi);
}
}Discarding Values
Use an underscore _ to ignore parts you do not need during deconstruction.
using System;
class Program
{
static (int, int, int) Rgb() => (255, 128, 0);
static void Main()
{
var (r, _, _) = Rgb();
Console.WriteLine("Red channel: " + r);
}
}Deconstructing into Existing Variables
You can assign to already-declared variables by leaving out the type names.
using System;
class Program
{
static void Main()
{
int a = 0, b = 0;
(a, b) = (10, 20);
Console.WriteLine(a + ", " + b);
}
}Swapping with Tuples
A neat trick: swap two variables in one line using tuple deconstruction, no temp variable needed.
using System;
class Program
{
static void Main()
{
int x = 1, y = 2;
(x, y) = (y, x);
Console.WriteLine("x=" + x + ", y=" + y);
}
}The Deconstruct Method
Your own classes can support deconstruction by defining a Deconstruct method with out parameters.
using System;
class Point
{
public int X, Y;
public Point(int x, int y) { X = x; Y = y; }
public void Deconstruct(out int x, out int y)
{
x = X;
y = Y;
}
}
class Program
{
static void Main()
{
var p = new Point(5, 9);
var (px, py) = p;
Console.WriteLine(px + ", " + py);
}
}Multiple Deconstruct Overloads
A class can offer several Deconstruct overloads exposing different numbers of values.
using System;
class Person
{
public string Name; public int Age; public string City;
public Person(string n, int a, string c) { Name = n; Age = a; City = c; }
public void Deconstruct(out string name, out int age)
{
name = Name; age = Age;
}
}
class Program
{
static void Main()
{
var p = new Person("Ada", 36, "London");
var (name, age) = p;
Console.WriteLine(name + ", " + age);
}
}Deconstruction in foreach
When looping over a collection of tuples, you can deconstruct each element right in the foreach header.
using System;
using System.Collections.Generic;
class Program
{
static void Main()
{
var pairs = new List<(string, int)>
{
("Ann", 30),
("Bob", 25)
};
foreach (var (name, age) in pairs)
Console.WriteLine(name + " is " + age);
}
}Putting It Together
Deconstruction makes code that returns or stores multiple values read cleanly, naming each part at the point of use.
using System;
class Program
{
static (int Quotient, int Remainder) Divide(int a, int b) => (a / b, a % b);
static void Main()
{
var (q, r) = Divide(17, 5);
Console.WriteLine("17 / 5 = " + q + " remainder " + r);
}
}Quick Check
Test your understanding of deconstruction.
Recap
Deconstruction splits a tuple or object into named variables in one statement. Use var (a, b) = ..., discard parts with _, swap variables, and deconstruct in foreach. Custom classes opt in with a Deconstruct method using out parameters, optionally overloaded.
using System;
class Program
{
static void Main()
{
var (a, b, c) = (1, 2, 3);
Console.WriteLine(a + b + c);
}
}Frequently asked questions
Is the “Deconstruction” lesson free?
Yes — the full text of “Deconstruction” is free to read here on the web, and the C# Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the C# Academy course, upgrade to CoddyKit PRO.
What will I learn in “Deconstruction”?
Unpack tuples into separate variables. You practise C# Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start C# Academy?
No prior experience is required. C# Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 3 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Deconstruction” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this C# Academy lesson?
Yes. Every C# Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.