Compare parent and child list

Question

0.00/5 (No votes)

See more:

Hi,

Compare 2 list and get the not matched list values from 2nd list and add it into the 1st list.

I have two list,

XML

List<Template> parent =  new Template[] {
           new Template(){ID = "1"},
           new Template(){ID = "2"},
           new Template(){ID = "3"},
           new Template(){ID = "4"},
           new Template(){ID = "5"},
           new Template(){ID = "6"},
       }.ToList();

XML

List<Template> child = new Template[] {
           new Template(){ID = "1"},
           new Template(){ID = "3"},
           new Template(){ID = "5"},
               new Template(){ID = "11"},
               new Template(){ID = "12"}
       }.ToList();

im expecting the parent list to be:
1
2
3
4
5
6
11
12

how to do this?

i did in this way, but its not working...,
parent.AddRange(parent.Except(child).ToList());

Posted 8-Apr-14 22:15pm

member0026

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Answer 1 · 2014-04-08T22:23:00

That's not going to work, even if you put it the other way round:

C#

parent.AddRange(child.Except(parent)).ToList();

Why not? Because

C#

Template a = new Template(){ID="1"};
Template b = new Template(){ID="1"};

Does not create one instance - it creates two different instances that have the same ID.The comparison for "are these the same?" compares the references, not the content, unless Template is a struct, so a and b are different!

You would need to use the other form of Except: http://msdn.microsoft.com/en-us/library/vstudio/bb336390(v=vs.90).aspx[^] which accepts a custom comparer to decide on equality (and swap child / parent over as well)

member0026 · Answer 2 · 2014-04-08T23:20:00

Solution 2

see i just give an example, i have two list with have same instance values...,

parent list have some values and child will have some values,

i want to get what are the values parent dont have but the child have, those child values to be added in parent list..... this is wht im expecting

Posted 8-Apr-14 23:20pm