imgen

public static class AnonymousExtension
{
    static void Main(string[] args)
    {
        var person = new { FirstName = "Scott", LastName = "Hunter", Sex = 'M', Age = 25 };

        var otherPerson = person.With(new { LastName = "Hanselman" });

        Console.WriteLine(otherPerson);
    }

imgen

// From below CodeProject article
// https://www.codeproject.com/Articles/894936/Manipulate-your-expression-trees-with-elegance

using System;
using System.Linq.Expressions;
using System.Reflection;

namespace ManipulateExpressionTrees
{
    public static class ReflectionHelpers

imgen

// Taken from https://codereview.stackexchange.com/a/133709/209350
var words = 
    Regex.Matches("SmallFireBall", @"([A-Z][a-z]+)")
    .Cast<Match>()
    .Select(m => m.Value);

var withSpaces = string.Join(" ", words);

imgen

using var conn = new SqlConnection(connectionString);
var connectionStringInfo = new SqlConnectionStringBuilder(connectionString);
var dbName = connectionStringInfo.InitialCatalog;
var sql = $"SELECT * FROM {tableName} WHERE 1 = 2";
using var command = new SqlCommand(sql, conn);
conn.Open();
using var reader = await command.ExecuteReaderAsync(CommandBehavior.KeyInfo);
var columnSchema = reader.GetColumnSchema();

imgen

public static void ToCSV(this DataTable dtDataTable, string strFilePath)  
{     
    StreamWriter sw = new StreamWriter(strFilePath, false);  
    //headers  
    for (int i = 0; i < dtDataTable.Columns.Count; i++)  
    {  
        sw.Write(dtDataTable.Columns[i]);  
        if (i < dtDataTable.Columns.Count - 1)  
        {  
            sw.Write(",");  

imgen

public static void OpenWithDefaultProgram(string path)
{
    Process fileopener = new Process();
    fileopener.StartInfo.FileName = "explorer";
    fileopener.StartInfo.Arguments = "\"" + path + "\"";
    fileopener.Start();
}

imgen

|                             Method |       Mean |    Error |   StdDev |     Median | Gen 0 | Gen 1 | Gen 2 |    Allocated |
|----------------------------------- |-----------:|---------:|---------:|-----------:|------:|------:|------:|-------------:|
|                        NoDuplicate | 1,178.0 ms | 23.31 ms | 49.17 ms | 1,154.3 ms |     - |     - |     - |            - |
|               DuplicateInTheMiddle |   556.9 ms | 11.49 ms | 14.53 ms |   558.1 ms |     - |     - |     - |            - |
|          NoDuplicateWithDictionary | 1,235.6 ms | 22.21 ms | 18.54 ms | 1,236.3 ms |     - |     - |     - | 1000000024 B |
| DuplicateInTheMiddleWithDictionary |   610.1 ms | 11.60 ms | 12.41 ms |   609.6 ms |     - |     - |     - | 1000000024 B |

Use number as index

|                             Method |       Mean |    Error |   StdDev |     Median | Gen 0 | Gen 1 | Gen 2 |    Allocated |

imgen

// Original question described in this video
// https://www.youtube.com/watch?v=XSdr_O-XVRQ

public int FindFirstDuplicate(int[] numbers)
{
    for(int i = 0; i < numbers.Length; i++)
    {
        var number = numbers[i];
        if (number < 0)
        {

imgen

public static string NamedFormat(string format, params object[] args)
{
    var newFormat = string.Empty;
    var paraIndex = 0;
    var paraNameIndexMap = new Dictionary<string, int>();
    for (int i = 0; i < format.Length; i++)
    {
        var ch = format[i];
        if (ch == '{')
        {

imgen

public static string FormatTimeSpan(TimeSpan timeSpan)
{
    var (minutes, seconds, milliseconds, microseconds) = (
        (int)timeSpan.TotalMinutes,
        timeSpan.Seconds,
        timeSpan.Milliseconds,
        int.Parse(timeSpan.ToString("ffffff").Substring(3))
    );

    return $"{minutes}m {seconds}s {milliseconds}ms {microseconds}μs";