Compare two list and Get boolean values from first List using LINQ [Resolved]

Posted by Allemahesh under LINQ on 10/19/2015 | Points: 10 | Views : 3420 | Status : [Member] [MVP] | Replies : 8

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I have a two IList say

List<Person> persons1 = new List<Person>
               {
                        new Person {Id = 1, Name = "Person 1"},
                        new Person {Id = 2, Name = "Person 2"},
                        new Person {Id = 3, Name = "Person 3"},
                        new Person {Id = 4, Name = "Person 4"}
               };

                List<Person> persons2 = new List<Person>
               {
                        new Person {Id = 1, Name = "Person 1"},
                        new Person {Id = 2, Name = "Person 2"},
                        new Person {Id = 3, Name = "Person 3"},
                        new Person {Id = 4, Name = "Person 5"},
               };

Now I want a LINQ query to compare these two lists such that the name in the two list should be same then return true else false.
Above example will return false as Name = 'Person 4' and Name ='Person 5' is different in two list.
Can any one help me.

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Posted by: Rajnilari2015 on: 10/19/2015 [Member] [Microsoft_MVP] [MVP] Platinum | Points: 50

2	You can also use EXCEPT var flag = persons1 .Select(n => n.Name) .Except(persons2.Select(n => n.Name)) .Count() == 0 ? true : false; if (flag) Console.WriteLine("Names are equal"); else Console.WriteLine("Names are not equal"); -- Thanks & Regards, RNA Team Allemahesh, if this helps please login to Mark As Answer. \| Alert Moderator

You can also use EXCEPT

 var flag = persons1

 .Select(n => n.Name)

.Except(persons2.Select(n => n.Name))

.Count() == 0 ? true : false;



if (flag) Console.WriteLine("Names are equal");

else Console.WriteLine("Names are not equal");

--
Thanks & Regards,
RNA Team

Allemahesh, if this helps please login to Mark As Answer. | Alert Moderator

Posted by: Rajnilari2015 on: 10/19/2015 [Member] [Microsoft_MVP] [MVP] Platinum | Points: 50

0	Try this var flag = persons1 .Where(x1 => !persons2.Any(x2 => x1.Name == x2.Name)) .Union(persons2.Where(x1 => !persons1.Any(x2 => x1.Name == x2.Name))) .Count() == 0 ? true : false; if (flag) Console.WriteLine("Names are equal"); else Console.WriteLine("Names are not equal"); -- Thanks & Regards, RNA Team Allemahesh, if this helps please login to Mark As Answer. \| Alert Moderator

Try this

 var flag = persons1

 .Where(x1 => !persons2.Any(x2 => x1.Name == x2.Name))

 .Union(persons2.Where(x1 => !persons1.Any(x2 => x1.Name == x2.Name)))

 .Count() == 0 ? true : false;



if (flag) Console.WriteLine("Names are equal");

else Console.WriteLine("Names are not equal");

--
Thanks & Regards,
RNA Team

Allemahesh, if this helps please login to Mark As Answer. | Alert Moderator

Posted by: Rajnilari2015 on: 10/19/2015 [Member] [Microsoft_MVP] [MVP] Platinum | Points: 50

0	Also try with SequenceEqual after maintaining the sort var flag = persons1.Select(n => n.Name).OrderBy(o=>o) .SequenceEqual(persons2.Select(n => n.Name).OrderBy(o => o)); if (flag) Console.WriteLine("Names are equal"); else Console.WriteLine("Names are not equal"); -- Thanks & Regards, RNA Team Allemahesh, if this helps please login to Mark As Answer. \| Alert Moderator

Also try with SequenceEqual after maintaining the sort

var flag = persons1.Select(n => n.Name).OrderBy(o=>o)
 .SequenceEqual(persons2.Select(n => n.Name).OrderBy(o => o));

 if (flag) Console.WriteLine("Names are equal");
 else Console.WriteLine("Names are not equal");

--
Thanks & Regards,
RNA Team

Allemahesh, if this helps please login to Mark As Answer. | Alert Moderator

Posted by: Sheonarayan on: 10/19/2015 [Administrator] HonoraryPlatinum | Points: 25

0	I was thinking to response and then saw your response. The EXCEPT method works like a charm. You are always faster. Keep it up Rajnilari2015. Regards, Sheo Narayan http://www.dotnetfunda.com Allemahesh, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Rajnilari2015 on: 10/19/2015 [Member] [Microsoft_MVP] [MVP] Platinum | Points: 25

0	Thank you Sir but I am your follower. -- Thanks & Regards, RNA Team Allemahesh, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Rajnilari2015 on: 10/19/2015 [Member] [Microsoft_MVP] [MVP] Platinum | Points: 25

0	Long time back I wrote an article on Compare Collections in C# ( http://beyondrelational.com/modules/2/blogs/80/posts/10652/compare-collections-in-c.aspx ) .You can refer that also for more ways to figure out the solution to the problem. -- Thanks & Regards, RNA Team Allemahesh, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Allemahesh on: 10/20/2015 [Member] [MVP] Silver | Points: 25

0	Thank you for your replay. Also I want to compare the Id as well as name. Can you please update the LINQ query. Allemahesh, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Rajnilari2015 on: 10/22/2015 [Member] [Microsoft_MVP] [MVP] Platinum | Points: 25

0	@Allemahesh, glad that it has helped you. I have answered based on question you asked for. However, here is an updated solution for your problem. var flag = persons1.Where(x1 => !persons2.Any(x2 => x1.Id == x2.Id && x1.Name == x2.Name )) .Union( persons2.Where(x1 => !persons1.Any(x2 => x1.Id == x2.Id && x1.Name == x2.Name ))) .Count() == 0 ? true : false; if (flag) Console.WriteLine("Names are equal"); else Console.WriteLine("Names are not equal"); Case 1: ID and Names are same Input List<Person> persons1 = new List<Person> { new Person {Id = 1, Name = "Person 1"}, new Person {Id = 2, Name = "Person 2"}, new Person {Id = 3, Name = "Person 3"}, new Person {Id = 4, Name = "Person 4"} }; List<Person> persons2 = new List<Person> { new Person {Id = 1, Name = "Person 1"}, new Person {Id = 2, Name = "Person 2"}, new Person {Id = 3, Name = "Person 3"}, new Person {Id = 4, Name = "Person 4"}, }; Output Names are equal Case 2: ID same but Name different Input List<Person> persons1 = new List<Person> { new Person {Id = 1, Name = "Person 1"}, new Person {Id = 2, Name = "Person 2"}, new Person {Id = 3, Name = "Person 3"}, new Person {Id = 4, Name = "Person 45"} }; List<Person> persons2 = new List<Person> { new Person {Id = 1, Name = "Person 1"}, new Person {Id = 2, Name = "Person 2"}, new Person {Id = 3, Name = "Person 3"}, new Person {Id = 4, Name = "Person 4"}, }; Result Names are not equal Case 3: ID different but Names are same Input List<Person> persons1 = new List<Person> { new Person {Id = 1, Name = "Person 1"}, new Person {Id = 2, Name = "Person 2"}, new Person {Id = 3, Name = "Person 3"}, new Person {Id = 4, Name = "Person 4"} }; List<Person> persons2 = new List<Person> { new Person {Id = 1, Name = "Person 1"}, new Person {Id = 2, Name = "Person 2"}, new Person {Id = 3, Name = "Person 3"}, new Person {Id = 44, Name = "Person 4"}, }; Result Names are not equal Hope this helps -- Thanks & Regards, RNA Team Allemahesh, if this helps please login to Mark As Answer. \| Alert Moderator

@Allemahesh, glad that it has helped you. I have answered based on question you asked for.
However, here is an updated solution for your problem.

var flag = persons1.Where(x1 => !persons2.Any(x2 => x1.Id == x2.Id

 && x1.Name == x2.Name ))

 .Union( persons2.Where(x1 => !persons1.Any(x2 => x1.Id == x2.Id

                        && x1.Name == x2.Name  )))

 .Count() == 0 ? true : false;



 if (flag) Console.WriteLine("Names are equal");

else Console.WriteLine("Names are not equal");

Case 1: ID and Names are same
Input

List<Person> persons1 = new List<Person>



               {



                        new Person {Id = 1, Name = "Person 1"},



                        new Person {Id = 2, Name = "Person 2"},



                        new Person {Id = 3, Name = "Person 3"},



                        new Person {Id = 4, Name = "Person 4"}



               };







            List<Person> persons2 = new List<Person>



               {



                        new Person {Id = 1, Name = "Person 1"},



                        new Person {Id = 2, Name = "Person 2"},



                        new Person {Id = 3, Name = "Person 3"},



                        new Person {Id = 4, Name = "Person 4"},



               };

Output

Names are equal

Case 2: ID same but Name different
Input

List<Person> persons1 = new List<Person>



               {



                        new Person {Id = 1, Name = "Person 1"},



                        new Person {Id = 2, Name = "Person 2"},



                        new Person {Id = 3, Name = "Person 3"},



                        new Person {Id = 4, Name = "Person 45"}



               };







            List<Person> persons2 = new List<Person>



               {



                        new Person {Id = 1, Name = "Person 1"},



                        new Person {Id = 2, Name = "Person 2"},



                        new Person {Id = 3, Name = "Person 3"},



                        new Person {Id = 4, Name = "Person 4"},



               };

Result
Names are not equal

Case 3: ID different but Names are same
Input

List<Person> persons1 = new List<Person>



               {



                        new Person {Id = 1, Name = "Person 1"},



                        new Person {Id = 2, Name = "Person 2"},



                        new Person {Id = 3, Name = "Person 3"},



                        new Person {Id = 4, Name = "Person 4"}



               };







            List<Person> persons2 = new List<Person>



               {



                        new Person {Id = 1, Name = "Person 1"},



                        new Person {Id = 2, Name = "Person 2"},



                        new Person {Id = 3, Name = "Person 3"},



                        new Person {Id = 44, Name = "Person 4"},



               };

Result
Names are not equal
Hope this helps

--
Thanks & Regards,
RNA Team

Allemahesh, if this helps please login to Mark As Answer. | Alert Moderator

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