Daily micro-tips for C#, SQL, performance, and scalable backend engineering.
Replace [^a-zA-Z0-9] with an empty string. string str = “This-is-my+++***RegexPattern&Text”; Regex rgx = new Regex(“[^a-zA-Z0-9]”); str = rgx.Replace(str, “”); OUTPUT: ThisismyRegexPatternText If you want to add an exception then you should add this character like this to the regex pattern (let’s assume you wish to exclude the ampersand): [^a-zA-Z0-9 &] string str = “This-is-my+++***RegexPattern&Text”; Regex rgx = […]
Let’s say we want to find the date of the first Friday of the 1st month. GetFirstFridayOfMonth(01.01.2023) =>06.01.2023 (The first Friday after 01.01.2023 is 06.01.2023) public DateTime GetFirstFridayOfMonth(DateTime date) { DateTime fridayDate = new DateTime(date.Year, date.Month, 1); //Let’s assume 1st Friday can start on the 1st of the month while (fridayDate.DayOfWeek != DayOfWeek.Friday) { fridayDate […]
Like converting XML to Json or Json to XML, you can also use Newtonsoft to get formatted Json. private static string FormatJson(string json) { dynamic parsedJson = JsonConvert.DeserializeObject(json); return JsonConvert.SerializeObject(parsedJson, Formatting.Indented); } Note: You can use var instead of dynamic. Both will work.
To do that easily, you can use Newtonsoft. // To convert an XML node contained in string xml into a JSON string XmlDocument doc = new XmlDocument(); doc.LoadXml(xml); string jsonText = JsonConvert.SerializeXmlNode(doc); // To convert JSON text contained in string json into an XML node XmlDocument doc = JsonConvert.DeserializeXmlNode(json); You can get more info from […]
Declare a local variable at the beginning of the View: @{ var yourStyle = “”; if(Model.Condition) { yourStyle = “float:left;”; //specific conditions and logic } else { yourStyle = “float:right;”; //any other conditions and logic } } and then just use it in your div: <div style=”@yourStyle”>
string useOfTrimEnd1= “Hello World !”.TrimEnd(‘!’); OUTPUT: Hello World string useOfTrimEnd2= “Hello World !!!!!!”.TrimEnd(‘!’); OUTPUT: Hello World Definition from Microsoft.com: TrimEnd(Char) Removes all the trailing occurrences of a character from the current string. TrimEnd() Removes all the trailing white-space characters from the current string. TrimEnd(Char[]) Removes all the trailing occurrences of a set of characters specified […]
The purpose of nameof is refactoring. For example, when you change the name of a class to which you refer through nameof somewhere else in your code you will get a compilation error which is what you want. If you didn’t use nameof and had just a plain string as a reference you’d have to full-text […]
The formal description for SelectMany() is: Projects each element of a sequence to an IEnumerable and flattens the resulting sequences into one sequence. SelectMany() flattens the resulting sequences into one sequence and invokes a result selector function on each element. The main difference is the result of each method while SelectMany() returns flattened results; Select() […]
C# includes a decision-making operator ?: called the conditional operator or ternary operator. It is the short form of the if-else conditions. Syntax: condition ? statement 1 : statement 2 The ternary operator starts with a boolean condition. If this condition evaluates to true then it will execute the first statement after ?, otherwise the second statement after : will […]
The null-coalescing operator ?? returns the value of its left-hand operand if it isn’t null; otherwise, it evaluates the right-hand operand and returns its result. The ?? operator doesn’t evaluate its right-hand operand if the left-hand operand evaluates to non-null. int? myValue = null; int result = myValue ?? -1; //result = -1; Syntax: p ?? q Here, p is […]
When you declare a variable in a .NET application, it allocates some chunk of memory in the RAM. This memory has three things: the name of the variable, the data type of the variable, and the value of the variable. That was a simple explanation of what happens in the memory, but depending on the […]
Let’s say we haveStartDate and EndDate and those are of type DateTime. If you want to have an int value as a result then: int theResult = (EndDate – StartDate).Days; And if you want to have a double value as a result then: double theResult = (EndDate – StartDate).TotalDays;
C# has a static constructor for this purpose. static class YourClass { static YourClass() { // perform initialization here } } A static constructor is used to initialize any static data, or to perform a particular action that needs to be performed once only. It is called automatically before the first instance is created or […]
We will try to return a string like: “I can text whatever I want with 4 different options in C#. ” with String Interpolation, String Format, String Concat, and String Builder. public class StringOptions { private string data1 = “4”; private string data2 = “C#”; public string StringInterpolation() => ($”I can text whatever I want […]
// Gets the value of associated with key “MyKey” from the local resource file (“~/MyPage.aspx.en.resx”) or from the default one (“~/MyPage.aspx.resx”) //The default location for resx files is App_LocalResources object keyValue = HttpContext.GetLocalResourceObject(“~/MyPage.aspx”, “MyKey”);
According to Microsoft: The lock keyword ensures that one thread does not enter a critical section of code while another thread is in the critical section. If another thread tries to enter a locked code, it will wait, block, until the object is released. The lock keyword calls Enter at the start of the block and Exit at the end of the block. lock keyword actually […]
DECLARE @MyValue int SELECT @MyValue = Column1 WHERE Column2 > 50 IF @MyValue IS NULL BEGIN RAISEERROR(‘This is my custom message from SQL.’, 16, 1) END ELSE SELECT MyValue END Use an error code within 11-16, or just use 16 for a “general” case. RAISERROR(‘This is my custom message from SQL.’,16,1) Why? Here’s summary of […]
The IndexOf() method returns the index number of the first matched character whereas the LastIndexOf() method returns the index number of the last matched character. using System; public class StringExample { public static void Main(string[] args) { string s1 = “Hello C#”; int first = s1.IndexOf(‘l’); int last = s1.LastIndexOf(‘l’); Console.WriteLine(first); Console.WriteLine(last); } } Output: […]
DateTime myDate; if(DateTime.TryParse(txtBirthDate.Text, out myDate)) { //Valid Date } else { //Invalid Date }
string myList = “9,3,12,43,2”; List<int> intList = myList.Split(‘,’).Select(int.Parse).ToList();
List<int> list = new List<int>() {1,2,3}; string.Join<int>(“,”, list) Join has generic overloads. It is so much easier to use it in that way to convert your list to the different types.
string sNumbers = “1,2,3,4,5”; var numbers = sNumbers.Split(‘,’).Select(Int32.Parse).ToList();
new[] {“,”, “/”}.Any(input.Contains) or you can use Regex Regex.IsMatch(input, @”[,/]”);
Table below shows the default value for the different predefined data types. Type Default sbyte, byte, short, ushort, int, uint, long, ulong 0 char ‘\x0000’ float 0.0f double 0.0d decimal 0.0m bool false object null string null As you can see, for the integral value types, the default value is zero. The default value for […]
@Html.TextArea(“Body”, null, new { cols = “55”, rows = “10” }) or
string myValueToSplit = “Istanbul, Tokyo, Seoul, Bangkok, Bali, Minsk, Belgrade, Kiev”; var theFirstValue = myValueToSplit.Split(‘,’)[0]; //OUTPUT: theFirstValue = “Istanbul” //You can change [0] as you wish. //For example, if you want to get Kiev, make it [7]
Constructor is a special method of the class that is automatically invoked when an instance of the class is created is called a constructor. The main use of constructors is to initialize the private fields of the class while creating an instance for the class. When you have not created a constructor in the class, the compiler […]
In C# (and many other languages) you will find that you use new often as it is fundamental to using types and classes. The new keyword does pretty much what it says: it will create a new instance of a class or type, assigning it a location in memory. Let me try and illustrate this. Company company; Here […]
To calculate the sum of a column in a DataTable use the DataTable.Compute method. DataTable dt; … int sumValue; sumValue = dt.Compute(“Sum(TheSumColumn)”, string.Empty);
Sometimes you want to run your code only when it is not in debug mode. You can use #IF DEBUG code block for this purpose #if DEBUG LogMail(“It is in debug mode, only add a log record.”) #else SendMail(“It is not in debug mode, so you can send e-mail.”) #endif