Display Linq result in a DataGridView

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using System.Drawing;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

public class Book {
    public String Title { get; set; }

    public override String ToString() {
        return Title;
    }
}
public class FormBooks : Form {

    static public Book[] Books =
    {
      new Book {Title="F"},
      new Book {Title="B"}
    };
    public FormBooks() {
        InitializeComponent();
    }

    private void FormStrings_Load(object sender, EventArgs e) {
        String[] books = { "F", "A", "B", "R", "B" };

        var query =
          from book in books
          where book.Length > 10
          orderby book
          select new { Book = book.ToUpper() };

        dataGridView1.DataSource = query.ToList();
    }
    private void InitializeComponent() {
        this.dataGridView1 = new System.Windows.Forms.DataGridView();
        ((System.ComponentModel.ISupportInitialize)(this.dataGridView1)).BeginInit();
        this.SuspendLayout();
        //
        // dataGridView1
        //
        this.dataGridView1.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
        this.dataGridView1.Dock = System.Windows.Forms.DockStyle.Fill;
        this.dataGridView1.Location = new System.Drawing.Point(10, 10);
        this.dataGridView1.Name = "dataGridView1";
        this.dataGridView1.Size = new System.Drawing.Size(272, 251);
        this.dataGridView1.TabIndex = 0;
        //
        // FormStrings
        //
        this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.ClientSize = new System.Drawing.Size(292, 271);
        this.Controls.Add(this.dataGridView1);
        this.Name = "FormStrings";
        this.Padding = new System.Windows.Forms.Padding(10);
        this.Text = "FormStrings";
        this.Load += new System.EventHandler(this.FormStrings_Load);
        ((System.ComponentModel.ISupportInitialize)(this.dataGridView1)).EndInit();
        this.ResumeLayout(false);

    }
    private System.Windows.Forms.DataGridView dataGridView1;
    public static void Main() {
        Application.Run(new FormBooks());
    }
}

    


DefaultIfEmpty Demo

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

public class MainClass {
    public static void Main() {
        string[] presidents = {"G", "H", "a", "H", "over", "Jack"};

        string name =
          presidents.Where(n => n.Equals("H")).DefaultIfEmpty("Missing").First(); Console.WriteLine(name);

    }
}

    


Without Using DefaultIfEmpty

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

public class MainClass {
    public static void Main() {

        string[] presidents = {"G", "H", "a", "H", "over", "Jack"};

        string jones = presidents.Where(n => n.Equals("H")).First();
        if (jones != null)
            Console.WriteLine("H was found");
        else
            Console.WriteLine("H was not found");

    }
}

    


Using DefaultIfEmpty in Where clause

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

public class MainClass {
    public static void Main() {
        string[] presidents = {"G", "H", "a", "H", "over", "Jack"};

        string jones = presidents.Where(n => n.Equals("H")).DefaultIfEmpty().First();
        if (jones != null)
            Console.WriteLine("H was found.");
        else
            Console.WriteLine("H was not found.");
    }
}

    


How queries can be executed immediately with operators such as ToList().

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

public class MainClass {
    public static void Main() {
        int[] numbers = new int[] { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };

        int i = 0;
        var q = (
            from n in numbers
            select ++i)
            .ToList();

        // The local variable i has already been fully
        // incremented before we iterate the results:
        foreach (var v in q) {
            Console.WriteLine("v = {0}, i = {1}", v, i);
        }
    }
}