Select Id(s) using Linq

Question

I have a DynamicNode named products which has product name and product id. I need to select all products id's to a array from the DynamicNode products using LINQ.

I tried something like

 @helper PrintProductYearChart(IEnumerable<DynamicNode> products)
{

    var res = products.select(x => x.filelds['Id']).ToAarray();
}

but its not working correctly.

Can any one help.Thanks in advance

in the products.select and x.fields['Id'] having error.Can't resolve the symbol — Arun, Jan 18 '14 at 09:02
What type of information do you need from me.you clarify above comment ? — Arun, Jan 18 '14 at 09:08
What is `DynamicNode` defined like? What properties and methods does it have? (Only with that knowledge, we can tell what `filelds` does or what to use instead.) — O. R. Mapper, Jan 18 '14 at 09:17
Also, is it really `filelds` (in capital letters: `FILELDS`) or `fileIds` (in capital letters: `FILEIDS`)? — O. R. Mapper, Jan 18 '14 at 11:06

BRAHIM Kamel · Accepted Answer · 2014-01-18T09:28:30.040

18

The Select LINQ operator Projects each element of a sequence into a new form. what you are you doing will project only one element with 'Id' as index so it will return one element only not an array of Id's

here you should specifiy that you want the ID

   @helper PrintProductYearChart(IEnumerable<DynamicNode> products)
    {

        var res = products.select(x => x.Id).ToArray();
    }

edited Jan 18 '14 at 09:28

answered Jan 18 '14 at 08:59

BRAHIM Kamel

13,492
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score 4 · Answer 2 · answered Jan 18 '14 at 12:18

class Program
{
    static void Main(string[] args)
    {
        var collection = new List<DynamicNode>(){
            new DynamicNode { Id = "1", Name = "name1"},
            new DynamicNode { Id = "2", Name = "name2"}
        };

        //Getting Ids using extension methods and lambda expressions
        string[] Ids = collection.Select(x => x.Id).ToArray();

        foreach (string id in Ids)
            Console.WriteLine(id);

        //Gettings ids using linq expression
        var linqIds = from s in collection
                           select s.Id;
        string[] lIds = linqIds.ToArray();

        foreach (string id in lIds)
            Console.WriteLine(id);

        Console.Read();
    }
}

class DynamicNode
{
    public string Id { get; set;}
    public string Name { get; set; }
}

Select Id(s) using Linq

2 Answers2