Get specified number of elements from the beginning using the Take() method.The following is our array.int[] marks = { 35, 72, 50, 90, 95, 85, 52, 67 };Now, use OrderByDescending to order the elements in Descending order. Then use the Take() method to get the elements.marks.AsQueryable().OrderByDescending(s => s).Take(5);Let us see the complete example.Example Live Demousing System; using System.Linq; using System.Collections.Generic; public class Demo {    public static void Main() {       int[] marks = { 35, 72, 50, 90, 95, 85, 52, 67 };       // top 5 student marks       IEnumerable selMarks = marks.AsQueryable().OrderByDescending(s => s).Take(5);       foreach (int res in selMarks) {          Console.WriteLine(res);       }    } }Output95 90 85 72 67

Firstly, set a sequence.List myList = new List { 1, 2, 3, 4 ,5};Now find the sum using the Queryable Sum() method.myList.AsQueryable().Sum();Example Live Demousing System; using System.Linq; using System.Collections.Generic; public class Demo {    public static void Main() {       List myList = new List { 1, 2, 3, 4 ,5};       Console.WriteLine("Sum of elements in a list...");       foreach (int res in myList) {          Console.WriteLine(res);       }       int sum = myList.AsQueryable().Sum();       Console.WriteLine("Sum = {0}", sum);    } }OutputSum of elements in a list... 1 2 3 4 5 Sum = 15

Find the sum of elements using the Linq Sum() method.Here’s our list with integer elements.List list = new List { 99, 34, 77, 75, 87, 35, 88};Now find the sum using the Sum() method.list.AsQueryable().Sum();The following is an example to find the sum of elements of a list with integer elements.Example Live Demousing System; using System.Linq; using System.Collections.Generic; public class Demo {    public static void Main() {       List list = new List { 99, 34, 77, 75, 87, 35, 88};       int res = list.AsQueryable().Sum();       Console.WriteLine("Sum = {0}", res);    } }OutputSum = 495

Set two sequences.double[] arr1 = { 10.2, 15.6, 23.3, 30.5, 50.2 }; double[] arr2 = { 15.6, 30.5, 50.2 };To get the difference between both the above arrays, use Except() method.IEnumerable res = arr1.AsQueryable().Except(arr2);The following is the complete code.Example Live Demousing System; using System.Linq; using System.Collections.Generic; class Demo {    static void Main() {       double[] arr1 = { 10.2, 15.6, 23.3, 30.5, 50.2 };       double[] arr2 = { 15.6, 30.5, 50.2 };       Console.WriteLine("Initial List...");       foreach(double ele in arr1) {          Console.WriteLine(ele);       }       IEnumerable res = arr1.AsQueryable().Except(arr2);       Console.WriteLine("New List...");       foreach (double a in res) {          Console.WriteLine(a);       }    } }OutputInitial List... 10.2 15.6 23.3 30.5 50.2 New List... 10.2 23.3

The TryParse() method converts the string representation of one or more enumerated constants to an equivalent enumerated object.Firstly, set an enum.enum Vehicle { Bus = 2, Truck = 4, Car = 10 };Now, let us declare a string array and set some values.string[] VehicleList = { "2", "3", "4", "bus", "Truck", "CAR" };Now parse the values accordingly using Enum TryParse() method.Example Live Demousing System; public class Demo {    enum Vehicle { Bus = 2, Truck = 4, Car = 10 };    public static void Main() {       string[] VehicleList = { "2", "3", "4", "bus", "Truck", "CAR" ... Read More

Bypass elements in an array and return the remaining elements using the SkipWhile() method.The following is our array −int[] marks = { 45, 88, 55, 90, 95, 85 };Now, let’s skip the elements greater than or equal to 60. The condition we have set using Lambda Expression.IEnumerable selMarks = marks.AsQueryable().OrderByDescending(s => s).SkipWhile(s => s >= 60);Example Live Demousing System; using System.Linq; using System.Collections.Generic; public class Demo {    public static void Main() {       int[] marks = { 45, 88, 55, 90, 95, 85 };       // skips elements above 60       IEnumerable selMarks = ... Read More

Skip elements from the end and return the remaining elements using the SkipLast() method.The following is an array.int[] marks = { 45, 88, 50, 90, 95, 85 };Now, let us skip two elements from the end using SkipLast() and Lambda Expressions, but this is done after arranging the elements in descending order.IEnumerable selMarks = marks.AsQueryable().OrderByDescending(s => s).SkipLast(2);Example Live Demousing System; using System.Linq; using System.Collections.Generic; public class Demo {    public static void Main() {       int[] marks = { 45, 88, 50, 90, 95, 85 };       IEnumerable selMarks = marks.AsQueryable().OrderByDescending(s => s).SkipLast(2);       Console.WriteLine("Skipped ... Read More

The numeric ("N") format specifier converts a number to a string of the following form −"-d,ddd,ddd.ddd…"Above,"-" is a negative number symbol if required,"d" is a digit (0-9), "," indicates a group separator,"." is a decimal point symbolExample Live Demousing System; using System.Globalization; class Demo {    static void Main() {       double val1 = -5566.789;       Console.WriteLine(val1.ToString("N", CultureInfo.InvariantCulture));       int val2 = 87987766;       Console.WriteLine(val2.ToString("N3", CultureInfo.InvariantCulture));    } }Output-5,566.79 87,987,766.000

Skip elements and return the remaining elements using the Skip() method.The following is an array.int[] marks = { 80, 55, 79, 99 };Now, let us skip 2 elements using Lambda Expressions, but this is done after arranging the elements in descending order.IEnumerable selMarks = marks.AsQueryable().OrderByDescending(s => s).Skip(2);Exampleusing System; using System.Linq; using System.Collections.Generic; public class Demo {    public static void Main() {       int[] marks = { 80, 55, 79, 99 };       IEnumerable selMarks = marks.AsQueryable().OrderByDescending(s => s).Skip(2);       Console.WriteLine("Skipped the result of 1st two students...");       foreach (int res in selMarks) {          console.WriteLine(res);       }    } }

Let’s say we want to remove whitespace from the following string str1.string str1 = "Brad Pitt";Now, use Regex Replace to replace whitespace with empty. Here, we have used System.Text.RegularExpressions.string str2 = System.Text.RegularExpressions.Regex.Replace(str1, @"\s+", "");Let us see the complete example.Example Live Demousing System; using System.Text.RegularExpressions; namespace Demo {    class Program {       static void Main(string[] args) {          string str1 = "Brad Pitt";          Console.WriteLine(str1);          string str2 = System.Text.RegularExpressions.Regex.Replace(str1, @"\s+", "");          Console.WriteLine(str2);       }    } }OutputBrad Pitt BradPitt