Linq :- Some of the handy statements

• These are some of the common interview question asked.

1)Remove Duplicates from a list

using System.Linq;  
 using System;  
 using System.Collections.Generic;  
 namespace GroupJoin  
 {  
   class Program  
   {  
     public static void Main()  
     {  
       List<string> list = new List<string>() { "anurag","anurag","abc","abc","xyz"};  
       Console.WriteLine("::Duplicate Strings in a List::");  
       var duplicateString = list.GroupBy(x => x)  
             .Where(group => group.Count() > 1)  
             .Select(group => group.Key);  
       foreach (var item in duplicateString)  
       {  
         Console.WriteLine(item);  
       }  
       Console.ReadLine();  
     }  
   }  
 }  

2)Remove duplicates in a given string

using System.Linq;  
 using System;  
 using System.Collections.Generic;  
 using System.Text.RegularExpressions;  
 namespace GroupJoin  
 {  
   class Program  
   {  
     public static void Main()  
     {  
       string input = "anurag;anurag;anurag2;anurag3;anurag4";  
       string output = string.Join(";", input.Split(';').Distinct().ToArray());  
       Console.WriteLine(output);  
       Console.ReadLine();  
     }  
   }  
 }  

3)Finding Smallest String

 using System.Linq;  
 using System;  
 using System.Collections.Generic;  
 namespace GroupJoin  
 {  
   class Program  
   {  
     public static void Main()  
     {  
       List<string> list = new List<string>() { "anurag","abhishek","xyz"};  
       Console.Write("Small String-> ");  
       Console.WriteLine(list.OrderByDescending(x => x.Length).Last());  
       Console.ReadLine();  
     }  
   }  
 }  

4)Remove duplicate characters of a string

using System.Linq;  
 using System;  
 using System.Collections.Generic;  
 namespace GroupJoin  
 {  
   class Program  
   {  
     public static void Main()  
     {  
       string s = "Dddduppplicaaate";   
       Console.Write("Removed Duplicate Characters -> ");  
       Console.WriteLine(new string(s.ToLower().ToCharArray().Distinct().ToArray()));  
       Console.ReadLine();  
     }  
   }  
 }  

5)Occurrences of string

 using System.Linq;  
 using System;  
 using System.Collections.Generic;  
 using System.Text.RegularExpressions;  
 namespace GroupJoin  
 {  
   class Program  
   {  
     public static void Main()  
     {  
       string s = "This is great.But is this really great ??";  
       Console.Write("String Occurences(this) -> ");  
       Console.WriteLine(Regex.Matches(s, "this", RegexOptions.IgnoreCase).Count);  
       Console.ReadLine();  
     }  
   }  
 } 

True For All and ALL(Check if all values are same)

using System;  
 using System.Collections.Generic;  
 using System.Linq;  
 namespace LINQ  
 {  
   class Program  
   {  
     static void Main(string[] args)  
     {  
       List<int> num1 = new List<int> { 2, 2, 2, 2 };  
       bool evenOrOdd = num1.TrueForAll(x => x == 2);  
       Console.WriteLine(evenOrOdd);  
       Console.ReadLine();  
     }  
   }  
 } 

Output

This gives the Same output:

 bool evenOrOdd= num1.All(x=>x==2);

Will update more on this post :)