C# Hashsets - Understand them, use them, LOVE them

[@tutorialsEUC]

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[@codeme8016]

I've worked with several languages including Java, C++, and Python. In my opinion C# (now dotnet core) has been the most comprehensive and clear syntax I've experienced with a lot of great new features with every new version. Just love it.

[@josephh8117]

yeah as much as I hate Microsoft, they do seem to take a lot of what people like about other languages and integrate them in various ways

[@codeme8016]

@@josephh8117 And I don't even have Windows. I've been a Linux user for decades.

[@kelvinclements]

Under the arrays your adding stuff into the list not the array

[@wimlotz713]

Hi there, someone probably mentioned this but your array section is adding to your list

[@salihgireniz3713]

dude introduced hashsets to us like it's our lord and saviour. Now I am a disciple.

[@antoninvojtesek1084]

Very well presented. Thank you.

[@VivekSingh-og6tv]

Thank you Brother 😇 your videos help me to learn about .Net c#.

[@tutorialsEUC]

Happy to hear that. I'm also excited to learn more and teach what I've learned :)

[@BluetonicUK28]

Just curious, is this quicker than LINQ using Distinct() ?

[@aliahmadi3902]

Thanks👍

[@ShivamSharma-sg7dk]

Great video. According to you, what are the most used methods for HashSets?

[@michaelgervasoni8009]

Great video. I find myself using collections more than hashsets in c#, because normally the data has key-value pairs (such as id and description). And in MVC drop downs for example normally require a key value pair like a selectlist. Do you have any thoughts on collections vs lists vs hashsets? After watching this I’m wondering if there are places I can simplify collections into hashsets, or do you find most real-life apps require collections because we normally have unique ids associated with our data?

[@tutorialsEUC]

Hi, I think that this is quite hard to answer because it relies on the purpose of your code. Fact is, that you should try to take the best data structure for your codes purpose. Usually you will be fine with any kind of collection and if you do not care about duplicates an array or a list will be your best bet. If you need kvps then a dictionary and if they you don't want duplicates, you pick the hashset. It really depends... :)

[@qwerty89993]

thanks!

[@rmcgraw7943]

The functionality you describe and show is great, but God forbid someone choses to do this, unless the data has already been retrieved, in application code. This should be done by the database; after all, it’s actually BUILT with data manipulation as it’s primary purpose. I can do all the stuff here with the Distinct, Group By, and Join clauses of SQL. In any case, the fact that the data is keyed on it’s actual hashcode is useful for various scenarios. In the data world, that’s called a natural key, and it means that the key IS the data, so it’s very fast at retrieving data. Using hashsets, of course, can very quickly lead to custom implementations of GetHashcode for objects added to the set. Good video all the same.

[@jonlbs7]

✨✨✨✨✨✨👍👍👍👍

[@yassinbenyahia6801]

so you are telling me that this is hashset this simple ? well let's go to see what we got at leet code