CODEWITHSUNDEEP
c#algorithm
Mikael Östberg
Mikael Östberg

Reputation: 17146

Linq query selecting comma separated list

I have a list of objects where the object has a string property that is a comma separated list of numeric Ids.

What is most efficient way to extract the comma separated values and get an int array?

Currently my solution is this:

var allCsvs = objects
    .Select(o => o.IdCsv); // the IdCsv is a string property, ie "1,2,3,4,5"
var allIds = string.Join(",", allCsvs);
var idArray = allIds.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries)
    .Select(id => Convert.ToInt32(id));

Any ideas on how to improve performance here?

Update:

The object might look like this:

class MyClass {
    public string IdCsv { get; set; }
}

And an instance of this class may have its string property IdCsv set to something like this: "1,2,3,4,5"

Upvotes: 1

Views: 5908

Answers (1)

Hamlet Hakobyan
Hamlet Hakobyan

Reputation: 33381

Try this:

internal class Csv
{
    public string CommaSepList { get; set; }
}


var allCsvs =
    new List<Csv>
        {
            new Csv
                {
                    CommaSepList = "1,2,3,4,,5"
                },
            new Csv
                {
                    CommaSepList = "4,5,7,,5,,"
                },
        };

int[] intArray =
    allCsvs
        .SelectMany(c => c.CommaSepList.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries))
        .Select(int.Parse)
        .ToArray();

Or

int[] intArray =
    allCsvs
        .SelectMany(c => c.CommaSepList.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries).Select(int.Parse))
        .ToArray();

Upvotes: 1

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