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The KeyValuePair class stores a pair of values in a single list with C#.Set KeyValuePair and add elements −var myList = new List(); // adding elements myList.Add(new KeyValuePair("Laptop", 20)); myList.Add(new KeyValuePair("Desktop", 40)); myList.Add(new KeyValuePair("Tablet", 60));Here is the code to learn how to work with KeyValuePair and display the keys and values −ExampleUsing System; using System.Collections.Generic; class Program { static void Main() { var myList = new List(); // adding elements myList.Add(new KeyValuePair("Laptop", 20)); myList.Add(new KeyValuePair("Desktop", 40)); myList.Add(new KeyValuePair("Tablet", 60)); foreach (var val in myList) { Console.WriteLine(val); } } }
Declare an array −int[] arr = { 5, 9, 2, 7 };Now to get the smallest element from an array, use the Min() method −arr.Min());Here is the complete code −Example Live Demousing System; using System.Linq; class Demo { static void Main() { int[] arr = { 5, 9, 2, 7 }; Console.WriteLine(arr.Min()); } }Output2
Set a list that has zero elements −List myList = new List();Now check whether the list is empty or null −Console.WriteLine(myList == null);Above, returns “False” i.e. the list is not null - the list is empty.Let us see the complete code −Example Live Demousing System; using System.Collections.Generic; using System.Linq; public class Demo { public static void Main() { List myList = new List(); // returns false i.e. an empty list (not a null list) Console.WriteLine(myList == null); } }OutputFalse
Declare a two dimensional array −string[, ] array = new string[3, 3];Set elements in the array −array[0, 0] = "One"; array[0, 1] = "Two"; array[0, 2] = "Three"; array[1, 0] = "Four"; array[1, 1] = "Five"; array[1, 2] = "Six"; array[2, 0] = "Seven"; array[2, 1] = "Eight"; array[2, 2] = "Nine";Now, get the upper bound to get the dimensions to loop over the array −int uBound0 = array.GetUpperBound(0); int uBound1 = array.GetUpperBound(1);Iterate through a nested loop, until the above two values as shown in the code below −Example Live Demousing System; using System.Collections.Generic; using System.Linq; public class Demo { ... Read More
To display the previous day, use the AddDays() method and a value -1 to get the previous day.Firstly, use the following to get the current day −DateTime.TodayNow, add -1 to the AddDays() method to get the previous day −DateTime.Today.AddDays(-1)The following is the code −Example Live Demousing System; using System.Collections.Generic; using System.Linq; public class Demo { public static void Main() { Console.WriteLine("Today = {0}", DateTime.Today); Console.WriteLine("Previous Day = {0}", DateTime.Today.AddDays(-1)); } }OutputToday = 9/4/2018 12:00:00 AM Previous Day = 9/3/2018 12:00:00 AM
To display the next day, use the AddDays() method and a value +1 to get the next day.Firstly, use the following to get the current day −DateTime.TodayNow, add 1 to the AddDays() method to get the next day −DateTime.Today.AddDays(1)The following is the code −Example Live Demousing System; using System.Collections.Generic; using System.Linq; public class Demo { public static void Main() { Console.WriteLine("Today = {0}", DateTime.Today); Console.WriteLine("Previous Day = {0}", DateTime.Today.AddDays(-1)); Console.WriteLine("Next Day (Tomorrow) = {0}", DateTime.Today.AddDays(1)); } }OutputToday = 9/4/2018 12:00:00 AM Previous Day = 9/3/2018 12:00:00 AM Next Day (Tomorrow) = 9/5/2018 12:00:00 AM
Use the DaysInMonth to display the number of days in a month.Add the year and month as a parameter for the DaysInMonth() method −DateTime.DaysInMonth(2018, 8);The following is an example −Example Live Demousing System; using System.Collections.Generic; using System.Linq; public class Demo { public static void Main() { Console.WriteLine("Today = {0}", DateTime.Today); int num_days = DateTime.DaysInMonth(2018, 8); Console.WriteLine("Days in August: "+num_days); } }OutputToday = 9/4/2018 12:00:00 AM Days in August: 31
The TimeSpan.From methods include FromDays, FromHours, FromMinutes, etc.To get the TimeSpan for all the methods// Days TimeSpan t1 = TimeSpan.FromDays(1); // Hours TimeSpan t2 = TimeSpan.FromHours(1); // Minutes TimeSpan t3 = TimeSpan.FromMinutes(1);The following is the code that works on all the TimeSpan methods −Example Live Demousing System; using System.Linq; public class Demo { public static void Main() { TimeSpan t1 = TimeSpan.FromDays(1); TimeSpan t2 = TimeSpan.FromHours(1); TimeSpan t3 = TimeSpan.FromMinutes(1); Console.WriteLine(t1); Console.WriteLine(t2); Console.WriteLine(t3); } }Output1.00:00:00 01:00:00 00:01:00
To illustrate it we are creating the following views −mysql> CREATE VIEW digits AS -> SELECT 0 AS digit UNION ALL -> SELECT 1 UNION ALL -> SELECT 2 UNION ALL -> SELECT 3 UNION ALL -> SELECT 4 UNION ALL -> SELECT 5 UNION ALL -> SELECT 6 UNION ALL -> SELECT 7 UNION ALL -> SELECT 8 UNION ALL -> SELECT 9; Query OK, 0 rows affected (0.08 sec) mysql> CREATE VIEW numbers AS SELECT ones.digit + ... Read More
Firstly, set two TimeSpans −TimeSpan t1 = TimeSpan.FromMinutes(1); TimeSpan t2 = TimeSpan.FromMinutes(2);To add it, use the Add() method −TimeSpan res = t1.Add(t2);ExampleUsing System; using System.Linq; public class Demo { public static void Main() { TimeSpan t1 = TimeSpan.FromMinutes(1); TimeSpan t2 = TimeSpan.FromMinutes(2); Console.WriteLine("First TimeSpan: "+t1); Console.WriteLine("Second TimeSpan: "+t2); // Adding TimeSpan res = t1.Add(t2); Console.WriteLine("Resultant TimeSpan: "+res); } }