Program:

The source code to demonstrate the use of the method as a condition in the Linq Where method, is given below. The given program is compiled and executed successfully on Microsoft Visual Studio.

//C# Program to demonstrate the use of the method 
//as a condition in Linq Where the method of List collection. 

using System;
using System.Collections.Generic;
using System.Linq;

class Demo
{
    static bool checkEven(int num)
    {
        if (num % 2 == 0)
            return true;
        else
            return false;
    }
    static void Main(string[] args)
    {
        List<int> intnums = new List<int>();

        intnums.Add(10);
        intnums.Add(11);
        intnums.Add(12);
        intnums.Add(13);
        intnums.Add(14);

        IEnumerable<int> result = intnums.Where(num => checkEven(num));

        Console.WriteLine("Even Numbers:");
        foreach (int even in result)
        {
            Console.WriteLine(even);
        }
    }
}

Output:

Even Numbers:
10
12
14
Press any key to continue . . .

Explanation:

In the above program, we created a list that contains integer numbers. Here we defined a static method to check the specified number is even or not.

IEnumerable<int> result = intnums.Where(num => checkEven(num));

Here we passed checkEven() method inside the where() method and filter even numbers.

Console.WriteLine("Even Numbers:");
foreach (int even in result)
{
    Console.WriteLine(even);
}

Here we printed filtered even numbers on the console screen.