how convert List<object> to Dictionary<object, string>?

Question

1.44/5 (2 votes)

See more:

Hi All,

i have a

C#

List<object> dataList

and i need to convert to

C#

Dictionary<object, string> SearchData = new Dictionary<object, string>();

?

Posted 25-Dec-14 22:18pm

Indukanth

Updated 18-Mar-19 19:08pm

Add a Solution

Comments

DamithSL 26-Dec-14 4:24am

so what will be the key and value of dictionary?

Indukanth 26-Dec-14 4:36am

in my datalist it is contain some text value..
its look like http://pbrd.co/1HKoh04

i need to give Id as the key and Subject as the value.

DamithSL 26-Dec-14 4:49am

how you create dataList? can't you use List<someclass> for your requirement rather than object list?

DamithSL 26-Dec-14 4:58am

update the question with how you create dataList, then we will able to provide better solution for you

Praveen Kumar Upadhyay 26-Dec-14 5:02am

Please update your question here.

2 solutions

Solution 2

C#

var res = list.ToDictionary(x => x, x => x);

The first lambda lets you pick the key, the second one picks the value.

You can play with it and make values differ from the keys, like this:

C#

var res = list.ToDictionary(x => x, x => string.Format("Val: {0}", x));

If your list contains duplicates, add Distinct() like this:

C#

var res = list.Distinct().ToDictionary(x => x, x => x);

EDIT To comment on the valid reason, I think the only reason that could be valid for conversions like this is that at some point the keys and the values in the resultant dictionary are going to diverge. For example, you would do an initial conversion, and then replace some of the values with something else. If the keys and the values are always going to be the same, HashSet<String> would provide a much better fit for your situation:

C#

var res = new HashSet<string>(list);
if (res.Contains("string1"))

Posted 26-Dec-14 0:08am

Member 10955785

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 · Accepted Answer · 2014-12-25T23:26:00

First off, don't create lists of object - it defeats the purpose of Generic Collections, which is strong typing. Use a list of your actual class type, or a var if this is returned by a Linq request.

Then just use the ToDictionary Linq method: http://msdn.microsoft.com/en-us/library/bb549277(v=vs.95).aspx[^]

C#

List<MyClass> mylist = new List<MyClass> {
           new MyClass(){Id = 208, Subject = "some text"},
           new MyClass(){Id = 209, Subject = "another text"},
           new MyClass(){Id = 210, Subject = "one text"},
           new MyClass(){Id = 211, Subject = "text mix"}};
Dictionary<int, MyClass> dict = mylist.ToDictionary(m => m.Id);