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Articles by karthikeya Boyini
Page 50 of 143
Date format validation using C# Regex
Use the DateTime.TryParseExact method in C# for Date Format validation.They method converts the specified string representation of a date and time to its DateTime equivalent. It checks whether the entered date format is correct or not.Exampleusing System; using System.Globalization; namespace Demo { class Program { static void Main(string[] args) { DateTime d; bool chValidity = DateTime.TryParseExact( "08/14/2018", "MM/dd/yyyy", CultureInfo.InvariantCulture, DateTimeStyles.None, out d); Console.WriteLine(chValidity); } } }OutputTrue
Read MoreC# Program to convert integer array to string array
Use the ConvertAll method to convert integer array to string array.Set an integer array −int[] intArray = new int[5]; // Integer array with 5 elements intArray[0] = 15; intArray[1] = 30; intArray[2] = 44; intArray[3] = 50; intArray[4] = 66;Now use Array.ConvertAll() method to convert integer array to string array −Array.ConvertAll(intArray, ele => ele.ToString());Let us see the complete code −Exampleusing System; using System.Text; public class Demo { public static void Main() { int[] intArray = new int[5]; // Integer array with 5 elements intArray[0] = 15; intArray[1] = 30; intArray[2] = 44; intArray[3] = 50; intArray[4] = 66; string[] strArray = Array.ConvertAll(intArray, ele => ele.ToString()); Console.WriteLine(string.Join("|", strArray)); } }Output15|30|44|50|66
Read MoreAbstract Classes in C#
An abstract class in C# includes abstract and non-abstract methods. A class is declared abstract to be an abstract class. You cannot instantiate an abstract class.Let us see an example, wherein we have an abstract class Vehicle and abstract method display()−public abstract class Vehicle { public abstract void display(); } The abstract class has derived classes: Bus, Car, and Motorcycle. The following is an implementation of the Bus derived class −public class Bus : Vehicle { public override void display() { Console.WriteLine("Bus"); } } ExampleLet us see the complete example of abstract classes in C# −using ...
Read MoreC# program to merge two sorted arrays into one
Set two arrays that you wish to merge −int[] arr1 = new int[5] { 5, 15, 25, 30, 47 }; int[] arr2 = new int[5] { 55, 60, 76, 83, 95 };Now take a third array that would merge both the above arrays −int[] merged = new int[10];The following is the code that merges two arrays into the third array in C# −Exampleusing System; using System.Collections.Generic; class Program { static void Main() { int i = 0; int j = 0; ...
Read MoreShow Bootstrap class
To show a Bootstrap class, use the .show class. You can try to run the following code to make a class visibleExample Bootstrap Example This class is visible. This is an example for hide class. This will be hidden.
Read MoreClear a list in C#
Firstly, set a list −List myList = new List(); myList.Add(45); myList.Add(77);Now, to clear the above list, use Clear() −myList.Clear();Here is the complete code −Exampleusing System; using System.Collections.Generic; public class Demo { public static void Main() { List myList = new List(); myList.Add(45); myList.Add(77); Console.WriteLine("Elements: "+myList.Count); myList.Clear(); Console.WriteLine("Elements after using clear: "+myList.Count); } }OutputElements: 2 Elements after using clear: 0
Read MoreHow to write the first program in C#?
The following is the first program in C# programming −Exampleusing System; namespace MyHelloWorldApplication { class MyDemoClass { static void Main(string[] args) { // display text Console.WriteLine("Hello World"); // display another text Console.WriteLine("Welcome!"); Console.ReadKey(); } } }OutputHello World Welcome!Let us see now what all it includes.using System; - the using keyword is used to include the System namespace in the program.namespace declaration - A namespace is a collection ...
Read MoreFlow control in try catch finally in C#
The flow control in try, catch, and finally can be understood using the following example. Here, we are dividing two numbers −Exampleusing System; namespace ErrorHandlingApplication { class DivNumbers { int result; DivNumbers() { result = 0; } public void division(int num1, int num2) { try { result = num1 / num2; } catch (DivideByZeroException e) { Console.WriteLine("Exception caught: {0}", e); ...
Read MoreC# program to find the index of an element in a List
Set a list and add elements −List val = new List(); // integer elements val.Add(35); val.Add(55); val.Add(68);Let’s say now we need to find the index of element 68. For that, use the IndexOf() method −int index = val.IndexOf(68);Here is the complete code −Exampleusing System; using System.Collections.Generic; public class Demo { public static void Main() { List val = new List(); // integer elements val.Add(35); val.Add(55); val.Add(68); // finding the index of element 68 int index = val.IndexOf(68); Console.WriteLine(index); } }Output2
Read MoreHow to declare and initialize a dictionary in C#?
Dictionary is a collection of keys and values in C#. Dictionary is included in the System.Collection.Generics namespace.To declare and initialize a Dictionary −IDictionary d = new Dictionary();Above, types of key and value are set while declaring a dictionary object. An int is a type of key and string is a type of value. Both will get stored in a dictionary object named d.Let us now see an example −Exampleusing System; using System.Collections.Generic; public class Demo { public static void Main() { IDictionary d = new Dictionary(); d.Add(1, 97); d.Add(2, ...
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