CODEWITHSUNDEEP
c#winformslistlinqsorting
qqqterr
qqqterr

Reputation: 13

How do I sort IList C # by date?

I have an IList:

IList[] info = new IList[2];
info[0] = Date;      //List<DateTime> item
info[1] = something; //List<double> item

So, I want sort info by dates in info[0]. Like that:

 Date.Sort((a, b) => a.CompareTo(b));

But when i'm trying to do it:

IEnumerable[] sortedEnum = info.OrderBy(info[0].Sort((a, b) => a.CompareTo(b)));

I get:

'System.Collections.IList' does not contain a definition for 'Sort' and no extension method 'Sort' accepting a first argument of type 'System.Collections.IList' could be found (are you missing a using directive or an assembly reference?).

Can someoene help me with this?

Upvotes: 0

Views: 762

Answers (2)

James Curran
James Curran

Reputation: 103575

Building on Marc's

List<(DateTime when, double value) list = info[0].Zip(info[1], (d,v)=> (d,v));

And as Magnetron points out, if you don't have C#7 yet,

var list = info[0].Zip(info[1], (d,v)=> Tuple.Create(d,v));
list.Sort((x,y) => x.Item1.compareTo(y.Item1));

Upvotes: 0

Marc Gravell
Marc Gravell

Reputation: 1064044

I think this is an X/Y problem. You're trying to solve a complex "sort two lists congruent to each-other". And ... you can do that, but it is very hard. Array.Sort has a suitable method for sorting two arrays in connection, but: not lists. You could try and do that, but frankly I think you're solving the wrong problem. If each DateTime and double is logically connected, then rather than having two lists: have one list with a composite value. For example:

var list = new List<(DateTime when, double value)>();
list.Add((dateX, valueX)); // your values...
list.Add((dateY, valueY));
list.Add((dateZ, valueZ));

list.Sort((x,y) => x.when.compareTo(y.when));

Here I'm using tuple-types, but the same thing can be done by declaring your own type to hold the composite values. You might also want to look into pre-sorted list container types, but that places more demands on the key value (uniquity, etc).

Upvotes: 2

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