CODEWITHSUNDEEP
c#asp.netremoveall
Solomon Closson
Solomon Closson

Reputation: 6217

How to use .RemoveAll in here?

Simple question here, but this has been killing me trying to get this to work...

I have a class, called Taxonomy. There is a property called, WebName, I get a list of Taxonomy classes, and would like to use .RemoveAll to remove any of the Taxonomy's within the list with the WebName.ToLower() equal to either "n/a" or "other". WebName property is of type string.

This is what I tried so far:

List<Taxonomy> theNeighborhoods = new List<Taxonomy>();
Taxonomy aNeighborhood = GetCachedNeighborhoodTaxonomy(); // Returns the Parent Taxonomy

theNeighborhoods = aNeighborhood.Children.ToList(); // This gives me a list of Taxonomy classes

How can I change theNeighborhoods List to only select values that do not have "n/a" or "other" in the WebName property of each Taxonomy?

theNeighborhoods = aNeighborhood.Children.ToList().RemoveAll(a => a.WebName.ToLower() == "n/a" || a.WebName.ToLower() == "other").ToList();

The above code gives me error, something like int has no extension ToList How to do this with .RemoveAll?

Upvotes: 0

Views: 153

Answers (3)

Becuzz
Becuzz

Reputation: 6866

You could do one of two things. First you could use a where from LINQ:

theNeighborhoods = aNeighborhood.Children.Where(a => a.WebName.ToLower() != "n/a" && a.WebName.ToLower() != "other").ToList();

Alternatively you could call RemoveAll after getting the list, like so:

theNeighborhoods = aNeighborhood.Children.ToList();
theNeighborhoods.RemoveAll(a => a.WebName.ToLower() == "n/a" || a.WebName.ToLower() == "other").ToList();

RemoveAll returns an int that represents how many items were removed. That is why you got the error you did. I suggest looking up the documentation on RemoveAll.

Upvotes: 2

Sriram Sakthivel
Sriram Sakthivel

Reputation: 73442

Try this:

theNeighborhoods = aNeighborhood
                   .Children
                   .Where(a => a.WebName.ToLower() != "n/a" &&
                               a.WebName.ToLower() != "other")
                   .ToList();

Your code doesn't work because RemoveAll returns an int not the List<T> or IEnumerable<T>.

Also worth noting that you're calling ToList twice, ToList isn't free. It involves creation of new array and copying the items. So avoid redundant use of ToList.

Upvotes: 4

Max
Max

Reputation: 246

Try only:

aNeighborhood.Children.ToList().RemoveAll(a => a.WebName.ToLower() == "n/a" || a.WebName.ToLower() == "other");

You cannot write ToList() because RemoveAll return the number of elements removed (int).

Upvotes: 0

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