Example of how to filter the elements of an array with LINQ in C#, based on the criteria

The first query selects all the fruit whose name begins with a letter from A to L, the second query selects all the fruit whose name begins with a letter from M to Z.

Code:

using System;
using System.Linq;

namespace ConsoleApplications
{
    class ArrayLinqDemo
    {
        static void Main(string[] args)
        {
            string[] al = { "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L" };
            string[] mz = { "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z" };

            // Create an array of type object Fruit
            Fruit[] fruits = new Fruit[7];

            fruits[0] = new Fruit("Ananas", 14, 10);
            fruits[1] = new Fruit("Apple", 8, 3);
            fruits[2] = new Fruit("Mango", 5, 16);
            fruits[3] = new Fruit("Orange", 23, 18);
            fruits[4] = new Fruit("Lemon", 9, 12);
            fruits[5] = new Fruit("Papaya", 11, 3);
            fruits[6] = new Fruit("Raspberry", 33, 23);

            Console.WriteLine("All elements of the array");
            foreach (Fruit f in fruits)
            {
                Console.WriteLine( f.ToString() );
            }

            // Select the fruit whose name starts with A~L
            Console.WriteLine();
            Console.WriteLine("Select the fruit whose name starts with A~L");
            var queryByNameAL =
                from fruit in fruits
                where ( al.Contains(fruit.Name.Substring(0,1)) )
                orderby fruit.Name ascending
                select fruit;

            foreach (Fruit f in queryByNameAL)
                Console.WriteLine("{0}", f.ToString());

            // Select the fruit whose name starts with M~Z
            Console.WriteLine();
            Console.WriteLine("Select the fruit whose name starts with M~Z");
            var queryByNameMZ =
                from fruit in fruits
                where (mz.Contains(fruit.Name.Substring(0, 1)))
                orderby fruit.Name ascending
                select fruit;

            foreach (Fruit f in queryByNameMZ)
                Console.WriteLine("{0}", f.ToString());
        }
    }

    /// <summary>
    /// A simple class to represent the fruits
    /// </summary>
    class Fruit
    {
        private string name;
        private int amount;
        private int weight;

        public string Name 
        { 
            get{ return name;}
            set { name = value; }
        }

        public int Amount
        {
            get { return amount; }
            set { amount = value; }
        }

        public int Weight
        {
            get { return weight; }
            set { weight = value; }
        }

        public Fruit(string n, int a, int w)
        {
            name = n;
            amount = a;
            weight = w;
        }

        public new string ToString()
        {
            return String.Format("{0} ({1}), [{2}]",name, amount, weight);
        }
    }
}

Result:

All elements of the array
Ananas (14), [10]
Apple (8), [3]
Mango (5), [16]
Orange (23), [18]
Lemon (9), [12]
Papaya (11), [3]
Raspberry (33), [23]

Select the fruit whose name starts with A~L
Ananas (14), [10]
Apple (8), [3]
Lemon (9), [12]

Select the fruit whose name starts with M~Z
Mango (5), [16]
Orange (23), [18]
Papaya (11), [3]
Raspberry (33), [23]