LINQ | Element Operator | Last

Last Updated : 24 May, 2019

The element operators are used to return a single, or a specific element from the sequence or collection. For example, in a school when we ask, who is the principal? Then there will be only one person that will be the principal of the school. So the number of students is a collection and the principal is the only result that comes from the collection. The LINQ Standard Query Operator supports 8 types of element operators:

ElementAt
ElementAtOrDefault
First
FirstOrDefault
Last
LastOrDefault
Single
SingleOrDefault

Last Operator

The Last operator is used to return the last element of the collection or sequence. Or return the last element which specifies the given condition. This method can be overloaded in two different ways:

Last<TSource>(IEnumerable<TSource>): This method returns the last element of the given collection or sequence.
Last<TSource>(IEnumerable<TSource>, Func<TSource, Boolean>): This method returns the last element according to the given condition.

Important Points:

It does not support query syntax in C# and VB.Net languages.
It support method syntax in both C# and VB.Net languages.
It present in both the Queryable and Enumerable class.
It throw an InvalidOperationException if the sequence does not contain the element which specifies the given condition, or the sequence is empty.

Example 1:

CSharp

// C# program to illustrate the 
// use of Last operator
using System;
using System.Linq;
using System.Collections.Generic;

class GFG {
    
    // Main Method
    static public void Main()
    {

        // Data source
        int[] sequence1 = {112, 44, 55, 66, 77, 777, 56};
        string[] sequence2 = {"Geeks", "GeeksforGeeks"};

        // Get the element which specifies
        // the given condition Using 
        // Last(Condition) function
        var result1 = sequence1.Last(seq => seq < 777);
        
        Console.WriteLine("Element: {0}", result1);

        // Get the only element of the 
        // sequence Using Last() function
        var result2 = sequence2.Last();
        
        Console.WriteLine("Element: {0}", result2);

        // This commented part will give 
        // InvalidOperationException because
        // the sequence does not contain element
        /*
            int[] sequence3 = {};
            var result3 = sequence3.Last();
            Console.WriteLine("Element: {0}", result3);
        */
    }
}

Output:

Element: 56
Element: GeeksforGeeks

Example 2:

CSharp

// C# program to find the last 
// name of the employee
using System;
using System.Linq;
using System.Collections.Generic;

// Employee details
public class Employee {

    public int emp_id
    {
        get;
        set;
    }

    public string emp_name
    {
        get;
        set;
    }

    public string emp_gender
    {
        get;
        set;
    }

    public string emp_hire_date
    {
        get;
        set;
    }

    public int emp_salary
    {
        get;
        set;
    }
}

class GFG {

    // Main method
    static public void Main()
    {
        List<Employee> emp = new List<Employee>() {
            
            new Employee() {emp_id = 209, emp_name = "Anjita", emp_gender = "Female",
                                    emp_hire_date = "12/3/2017", emp_salary = 20000},

            new Employee() {emp_id = 210, emp_name = "Soniya", emp_gender = "Female",
                                    emp_hire_date = "22/4/2018", emp_salary = 30000},

            new Employee() {emp_id = 211, emp_name = "Rohit", emp_gender = "Male",
                                  emp_hire_date = "3/5/2016", emp_salary = 40000},

            new Employee() {emp_id = 212, emp_name = "Supriya", emp_gender = "Female",
                                      emp_hire_date = "4/8/2017", emp_salary = 40000},

            new Employee() {emp_id = 213, emp_name = "Anil", emp_gender = "Male",
                                emp_hire_date = "12/1/2016", emp_salary = 40000},

            new Employee() {emp_id = 214, emp_name = "Anupriya", emp_gender = "Female",
                                      emp_hire_date = "17/6/2015", emp_salary = 50000},
        };

        // Query to find the name
        // of the last employee
        // Using Last method
        var res = emp.Select(e => e.emp_name).Last();
        
        Console.WriteLine("Employee name: {0}", res);
    }
}