A lambda expression in C# describes a pattern.Lambda Expressions has the token => in an expression context. This is read as “goes to” operator and used when a lambda expression is declared.Here, we are finding the first occurrence of the element greater than 50 from a list.list.FindIndex(x => x > 50);Above the token => is used. The same is shown below −Example Live Demousing System; using System.Collections.Generic; class Demo {    static void Main() {       List list = new List { 44, 6, 34, 23, 78 };       int res = list.FindIndex(x => x > 50);       Console.WriteLine("Index: "+res);    } }OutputIndex: 4

Keywords are reserved words predefined to the C# compiler. These keywords cannot be used as identifiers. However, if you want to use these keywords as identifiers, you may prefix the keyword with the @ character.The following are the two types of keywords in C#.Reserved KeywordsabstractasbaseBoolbreakbytecasecatchcharcheckedClassconstcontinuedecimaldefaultdelegatedoDoubleelseenumeventexplicitexternfalseFinallyfixedfloatforforeachgotoifImplicitinin (generic modifier)intinterfaceinternalisLocklongnamespacenewnullobjectoperatorOutout (generic modifier)overrideparamsprivateprotectedpublicReadonlyrefreturnsbytesealedshortsizeofstackallocstaticstringstructswitchthisthrowTruetrytypeofuintulonguncheckedunsafeUshortusingvirtualvoidvolatilewhileContextual Keywordsaddaliasascendingdescendingdynamicfromgetglobalgroupintojoinletorderbypartial (type)partial(method)removeselectset

To display large Fibonacci numbers, try the following login and code.Here, we have set the value of n as the series. Set it to get the Fibonacci number. Below, we have set it to 100 to get the first 100 Fibonacci numbers.Since the first two numbers in a Fibonacci series are 0 and 1. Therefore, we will set the first two values.int val1 = 0, val2 = 1;The following is the complete code to display large Fibonacci numbers.Example Live Demousing System; public class Demo {    public static void Main(string[] args) {       int val1 = 0, val2 = ... Read More

To display Armstrong numbers from 1 to 100, firstly use a while loop.Examplewhile (val

A regular expression is a pattern that could be matched against an input text. A pattern consists of one or more character literals, operators, or constructs.Let us see an example to display the words starting with the letter ‘M’ using Regex.Example Live Demousing System; using System.Text.RegularExpressions; namespace Demo {    class Program {       private static void showMatch(string text, string expr) {          Console.WriteLine("The Expression: " + expr);          MatchCollection mc = Regex.Matches(text, expr);          foreach (Match m in mc) {             Console.WriteLine(m);   ... Read More

To pass arrays to methods, you need to pass an array as a method argument.int displaySum(int[] arr, int size) { }Now call it −sum = d.displaySum(myArr, 5 ) ;Example Live Demousing System; namespace Test {    class Demo {       int displaySum(int[] arr, int size) {          int i;          int sum = 0;          for (i = 0; i < size; ++i) {             sum += arr[i];          }          return sum;       }           static void Main(string[] args) {          Demo d = new Demo();          int [] myArr = new int[] {59, 34, 76, 65, 12, 99};          int sum;          sum = d.displaySum(myArr, 5 ) ;          /* output the returned value */          Console.WriteLine( "Sum: {0} ", sum );          Console.ReadKey();       }    } }OutputSum: 246

To quickly convert decimal to other bases, use Stacks. Let us see an example.Firstly, I have set the variable “baseNum” as 2int baseNum = 2;In the same way, if you want another base, then −// base 8 int baseNum = 8; // base 10 int baseNum = 10;After getting the value, set a stack and get the values by getting the remainder and other calculations as shown below.Here, n is the decimal number.Stack s = new Stack(); do {    s.Push(n % baseNum);    n /= baseNum; } while (n != 0);After using the stack, pop out the elements. ... Read More

First, set a two-dimensional array.int[, ] arr = new int[10, 10];Now, get the elements from the user −for (i = 0; i < m; i++) {    for (j = 0; j < n; j++) {       arr[i, j] = Convert.ToInt16(Console.ReadLine());    } }Let us see the complete example to display the matrix.Example Live Demousing System; using System.Linq; class Demo {    static void Main() {       int m, n, i, j;       // rows and columns of the matrix+       m = 2;       n = ... Read More

To perform matrix addition, take two matrices. Enter the rows and columns of matrix one and matrix two. Remember, both the matrix should be a square matrix to add them.Now add elements to both the matrices. Declare a new array and add both the arrays in it.arr3[i, j] = arr1[i, j] + arr2[i, j];Let us see the complete code −Exampleusing System; using System.Linq; class Demo {    static void Main() {       int m, n, i, j;           Console.Write("Enter number of rows and columns of the matrix ");       ... Read More

Dictionary is a collection of keys and values in C#. Dictionary is included in the System.Collection.Generics namespace. Dictionary is a generic type and returns an error if you try to find a key which is not there.List collection is a generic class and can store any data types to create a list.A list is a group of items −List myList = new List() {    "Maths",    "English", "   Science" };Dictionary is a set of key-value pairs.Dictionary d = new Dictionary(); d.Add("squash", 1); d.Add("football", 2); d.Add("rugby", 3);Looping is easier and faster in a list and access element using index ... Read More