Compare two dictionaries of different size in C#

Question

1.00/5 (1 vote)

See more:

I have two different dictionaries of different size, can we compare both these and extract the values which are not there in dictionary 1?

What I have tried:

I have two different dictionaries of different size, can we compare both these and extract the values which are not there in dictionary 1?

Posted 13-Jul-18 22:38pm

Member 13911288

Updated 13-Jul-18 22:47pm

Add a Solution

1 solution

Add a Solution

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

OriginalGriff · Answer 1 · 2018-07-13T22:48:00

Solution 1

Use the Linq Except method:

C#

Dictionary<string, string> d1 = new Dictionary<string, string>();
d1.Add("Joe", "2, Barfield Way");
d1.Add("Mike", "17, Apollo Avenue");
d1.Add("Jane", "69, Lance Drive");
Dictionary<string, string> d2 = new Dictionary<string, string>();
d2.Add("Joe", "2, Barfield Way");
d2.Add("Jane", "69, Lance Drive");
var diff = d1.Except(d2);

Posted 13-Jul-18 22:48pm

OriginalGriff

Comments

Member 13911288 14-Jul-18 4:55am

Thanks for the answer, my dictionaries have time in HH:mm format. Dictionary 1 has time from 00:00 to 23:45 and dictionary two has random hours like 00:15, 00:45, 15:00. Here's my dictionary in brief

Dictionary1
(startdttm1,"00:00")
(enddttm1,"00:15")
(startdttm2,"00:15")
(enddttm2,"00:30")
(startdttm3,"00:30")
(enddttm4,"00:45")
......
(startdttmn,"23:30")
(enddttmn,"23:45")

now my second dictionary has booking in random order

(startdttm1,"00:00")
(enddttm1,"00:30")
(startdttm2,"02:00")
(enddttm1,"02:30")

so now how to compare dictionary 1 to dictionary 2 and I need to pick values from dictionary 1 which are greater in values than dictionary 2? I am able to DateTime.Parse and compare two times but the thing is if I am failing to retrieve the exact values from dictionary 1 which are greater than all the values in dictionary 2.

Dictionary 1 is large and Dictionary 2 is small.

OriginalGriff 14-Jul-18 5:10am

First off, change your storage.
Never keep data in strings if there is a more appropriate datatype - which in this case is Timespan, which has comparison operators.
Storing the start and end times like that is also a bad idea, as all comparisons will be string based - and they are done by character by character comparison, with the whole result depending on the result of the first difference. That menas that any idea of sort order goes out the window.
Second, don't use a dictionary.
DIctionaries are not sorted: they are hashed so they do not preserve the order in which you insert values.

I think you have some major problems here, and no amount of patching is going to solve them in a "good way" - you need to go back to the start of your data collection, and improve the whole storage process - it's fatally flawed at the moment and will only continue to give you more and more problems until you sort it properly.

Member 13911288 14-Jul-18 5:14am

so what do you suggest in this case where I need to compare two collections of datetime values?

OriginalGriff 14-Jul-18 5:26am

I can't suggest anything - I have no idea what your homework is asking you to do, or what the rest of your code looks like.
I have no idea why you are storing what, or where you get it from - only you know that!

And as I said - your whole data storage is the problem and needs to be revised. Get that right, and the comparison either becomes obvious or possibly unnecessary - either way, there is no point in trying to fix a problem here if the whole basis of the rest of your code is going to have to change.

Member 13911288 14-Jul-18 5:29am

What if I convert the two dictionaries into List of Values and compare both and extract only the values which are greater than list 2? Can you suggest anything on this?

OriginalGriff 14-Jul-18 5:40am

How would I know? I have no idea what effects that would have on the rest of your code! :laugh:

One of the hardest things a developer has to learn is when to let go. When the effort you have invested in getting to this point has to be chalked up to experience and a pile of work thrown away because of a fundamental problem caused by a bad decision right at the start.
And I know you don't want to do that. But trust me, you have made the coding equivalent of trying to design a racing bicycle by starting with a single wheel and the motor out of a Mack truck...

Compare two dictionaries of different size in C#

1 solution

Solution 1

Add your solution here

Preview 0

Compare two dictionaries of different size in C#

1 solution

Solution 1

Add your solution here

Preview 0

Existing Members

...or Join us