C# Tuples

A tuple in C# allows us to store elements of different data types. For example,

var student = ("Taylor", 27, "Orlando");

Here, student is a tuple that consists of two string elements ("Taylor" and "Orlando") and an integer element (27).

Create Tuple in C#

C# provides various ways for creating tuples. We will learn about the following methods:

1. Using Parentheses
2. Using the Create() Function

Let's understand both of these processes in detail.

1. C# Tuple Using Parentheses

We can create a tuple by directly assigning different values using parentheses (). For example,

using System;

class Program {
    public static void Main() {
        // create a tuple containing 3 elements
        var student= ("Taylor", 5, "Orlando");
        Console.WriteLine(student);
    }
}

Output

("Taylor", 5, "Orlando")

In the above example, we have created a tuple without mentioning the datatypes of the elements.

In this way, we can store data elements of different data types inside a tuple without mentioning the datatype.

using System;

class Program {
	public static void Main() {
	    
                (string,int,string) student = ("Taylor", 5, "Orlando");
 
                 Console.WriteLine(student);
	}
}
// Output: (Taylor, 5, Orlando)

2. C# Tuple using Create() Method

In C# we can also use the Create() method to create a tuple without having to mention the datatypes of the tuple elements.

The syntax for creating tuple using Create() is:

var t1 = Tuple.Create(value);

To understand it clearly, let's see an example:

using System;
					
class Program {
    public static void Main() {
        // create a tuple containing 3 elements 
         var programming = Tuple.Create("codemy", "java", 12);
        Console.WriteLine(programming);
    }
}

Output

(codemy, java, 12)

In the above example, we have used the Create() method to create a tuple named programming that contains 3 elements.

Note: While creating a tuple using the Create() method it can only include a maximum of eight elements.

Access Tuple Elements

In the previous example, we have directly displayed the whole tuple. However, it is possible to access each element of the tuple.

In C# each element of the tuple is associated with a default name.

• first element - Item1
• second element - Item2
• and so on

We can access elements of tuple using the default name. For example,

using System;
					
class Program {
	public static void Main() {
	    
	    var subjects = Tuple.Create("Science", "Maths", "English");
        // access the first element 
        Console.WriteLine("The first element is " + subjects.Item1);
        // access the second element
        Console.WriteLine("The second element is " +subjects.Item2);
	}
}

Output

The first element is Science
The second element is Maths

In the above example:

• subjects.Item1 - accesses the first element
• subjects.Item2 - accesses the second element

Change Value of the Tuple Element

We can change the value of data inside a tuple. To change the elements of the tuple, we can reassign a new value to the default name. For example,

using System;
					
class Program {
    public static void Main() {
        var roll_num = (5, 7, 8, 3);
	    
         // original tuple
         Console.WriteLine("Original Tuple: " + roll_num);
	    
        // replacing the value 7 with 6
        roll_num.Item2 = 6; 
         Console.WriteLine("Changing value of 2nd element to " + roll_num.Item2);
         Console.WriteLine("Modified Tuple: " + roll_num);
    }
}

Output

Original Tuple: (5, 7, 8, 3)
Changing value of 2nd element to 6
Modified Tuple: (5, 6, 8, 3)

In the above example, we have replaced the value of the 2nd element with 6.

using System;

class Program {
	public static void Main() {
	    var t1= Tuple.Create("Taylor", "Jack");
	    t1.Item2 = "Monica";
	    Console.WriteLine(t1.Item2);
	}
}

Property or indexer 'Tuple<string, string>.Item2' cannot be assigned to -- it is read only

Nested Tuple

We can create a tuple inside another tuple. A tuple within a tuple is called a nested tuple. For example,

using System;
					
class Program {
    public static void Main() {
	    
         var myTuple= Tuple.Create("Taylor", "Jack", Tuple.Create(7, 8, 9));
        Console.WriteLine("The elements inside myTuple: " + myTuple); 
    }
}

Output

The elements inside myTuple: (Taylor, Jack, (7, 8, 9))   

Here, we have a tuple (7, 8, 9) inside the myTuple tuple. This is called a nested tuple.

using System;
					
class Program {

    // method
    static void displayTuple(Tuple<int, string, int>numbers) {
        Console.WriteLine("Tuple: " + numbers);
    }
    
    public static void Main() {
        // create a tuple 
        var numbers = Tuple.Create(1, "John", 2);
        
        // passing the tuple inside method as a parameter 
        displayTuple(numbers); 
    }
}

Tuple: (1, John, 2)

static void displayTuple(Tuple<int, string, int>numbers) {
        Console.WriteLine("Tuple: " + numbers);
    }

using System;
					
class Program {
    public static void Main() {
	    
         // the return value of displaySalary() is stored in employee tuple
        var employee = displaySalary();
	    
        // accessing the second element of employee  
        Console.WriteLine(employee.Item2);
	    
    } 
    // the return type of displaySalary() method is a tuple containing three elements 
    static Tuple<string, int, int> displaySalary() {
        return Tuple.Create("Selena", 15000, 23);
    }
}

The first element of tuple: 1

var t1= (Subject: "Math", Grade: 2);

using System;
					
class Program {
    public static void Main() {
        var t1 = (Subject: "Math", Grade: 2);
	    
        // accessing the element of t1 using their names
        Console.WriteLine(t1.Subject);
        Console.WriteLine(t1.Grade);
    } 
}

Math
2