Server Side Programming Articles - Page 1664 of 2650

Convert a string representation of number to an integer, using the int.Parse or Convert.ToInt32 method in C#. If the string cannot be converted, then the int.Parse or Convert.ToInt32 method returns an exceptionConvert.ToInt32 allows null value, it doesn't throw any errors Int.parse does not allow null value, and it throws an ArgumentNullException error.Example Live Democlass Program {    static void Main() {       int res;       string myStr = "5000";       res = int.Parse(myStr);       Console.WriteLine("Converting String is a numeric representation: " + res);       Console.ReadLine();    } }OutputConverting String is a ... Read More

For deleting all the folders and its respective directories we can make us System.IO namespace available in C#. The DirectoryInfo() class provides the details of all sub directories and file in a directory.ExampleLet us consider a directory Demo having two sub directories and has some files like below.using System.IO; namespace DemoApplication {    class Program {       static void Main(string[] args) {          DirectoryInfo di = new DirectoryInfo(@"D:\Demo");          foreach (DirectoryInfo dir in di.GetDirectories()) {             foreach (FileInfo file in dir.GetFiles()) {           ... Read More

We can make use of Reflection to fetch a property value dynamically.Reflection provides objects (of type Type) that describe assemblies, modules and types. We can use reflection to dynamically create an instance of a type, bind the type to an existing object, or get the type from an existing object and invoke its methods or access its fields and properties. If we use attributes in our code, reflection enables us to access them.The System.Reflection namespace and System.Type class play an important role in .NET Reflection. These two works together and allows us to reflect over many other aspects of a ... Read More

In .Net, every string has a character set and encoding. A character encoding tells the computer how to interpret raw zeroes and ones into real characters. It usually does this by pairing numbers with characters. Actually, it is the process of transforming a set of Unicode characters into a sequence of bytes.We can use Encoding.GetString Method (Byte[]) to decodes all the bytes in the specified byte array into a string. Several other decoding schemes are also available in Encoding class such as UTF8, Unicode, UTF32, ASCII etc. The Encoding class is available as part of System.Text namespace.string result = Encoding.Default.GetString(byteArray);Example Live ... Read More

This error occurs when a looping process is being running on a collection (Ex: List) and the collection is modified (data added or removed) during the runtime.Example Live Demousing System; using System.Collections.Generic; namespace DemoApplication {    public class Program {       static void Main(string[] args) {          try {             var studentsList = new List {                new Student {                   Id = 1,                   Name = "John"                },                new Student {                   Id = 0,                   Name = "Jack"                },                new Student {                   Id = 2,                   Name = "Jack"                }             };             foreach (var student in studentsList) {                if (student.Id

A List of string can be converted to a comma separated string using built in string.Join extension method.string.Join(", " , list);This type of conversion is really useful when we collect a list of data (Ex: checkbox selected data) from the user and convert the same to a comma separated string and query the database to process further.Example Live Demousing System; using System.Collections.Generic; namespace DemoApplication {    public class Program {       static void Main(string[] args) {          List fruitsList = new List {             "banana",             ... Read More

There are two ways that we can verify an exception in unit testing.Using Assert.ThrowsExceptionUsing ExpectedException Attribute.ExampleLet us consider a StringAppend method which throws an exception needs to be tested.using System; namespace DemoApplication {    public class Program {       static void Main(string[] args) {       }       public string StringAppend(string firstName, string lastName) {          throw new Exception("Test Exception");       }    } }Using Assert.ThrowsExceptionusing System; using DemoApplication; using Microsoft.VisualStudio.TestTools.UnitTesting; namespace DemoUnitTest {    [TestClass]    public class DemoUnitTest {       [TestMethod]       public void ... Read More

Stream is the abstract base class of all streams and it Provides a generic view of a sequence of bytes. The Streams Object involve three fundamental operations such as Reading, Writing and Seeking. A stream be can be reset which leads to performance improvements.A byte array can be converted to a memory stream using MemoryStream Class.MemoryStream stream = new MemoryStream(byteArray);ExampleLet us consider a byte array with 5 values 1, 2, 3, 4, 5. Live Demousing System; using System.IO; namespace DemoApplication {    class Program {       static void Main(string[] args) {          byte[] byteArray = new ... Read More

A delegate is a type that represents references to methods with a particular parameter list and return type. When we instantiate a delegate, we can associate its instance with any method with a compatible signature and return type. We can invoke (or call) the method through the delegate instance.Func DelegateFunc is a generic delegate included in the System namespace. It has zero or more input parameters and one out parameter. The last parameter is considered as an out parameter. This delegate can point to a method that takes up to 16 Parameters and returns a value.Below is the Func delegate ... Read More

A string having number can be validated using int.TryParse or int.Parse.Int.Parse throws an exception if it cannot parse the string to an integer, whereas Int.TryParse returns a bool indicating whether it succeeded. Also, Int.TryParse has an out parameter which has the value of the parsed string.Example Live Demousing System; namespace DemoApplication {    class Program {       static void Main(string[] args) {          string numberString = "123";          int number = 0;          if(int.TryParse(numberString, out number)) {             Console.WriteLine($"Try Parse Interger Number: {number}");     ... Read More