Look, I’ve been programming the LINQ operators in C# since they began and have been quick to adopt them, but I ALWAYS forget how to use Aggregate. I end up searching in my code for how I’ve used it in the past or going back to the same of beginner websites to remember.
Anybody have a good way to remember how to use it? Some useful mnemonic or catchphrase or mantra?
What are you forgeting?
It’s (init, (prev, next) => something)
At least that’s how I remember it. Same as fold in other languages so you pick up these similar patterns across languages.
Okay, this is nice. I can remember this. Thanks!
Aggregate is a reducer. It reduces an Enumerable to one value by executing reducer over each element, using the last value and current value, with the initial value being used as the value for last in the first iteration. The selector function is optional.
or
In Javascipt, this is the reduce method, with the arguments swapped.
You can implement Sum using Aggregate:
I ALWAYS forget how to use Aggregate.
I’m curious: how often do you find yourself needing it? Which aggregates are you implementing with it? I use it maybe… once every other year?
https://docs.microsoft.com/en-us/dotnet/api/system.linq.enumerable.aggregate?view=net-5.0