CODEWITHSUNDEEP
c#asp.net
user9065477
user9065477

Reputation:

Get first item of list value of each object

I have a list where I can get alot of objects.

List<string[]> registros

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That I want to do is to get register 0 of each object, for example object 0

enter image description here

I want to get only "CORP" value and so on with all objects. So I try 

foreach (var reg in registros[0])
{
    var list = new[]
    {
        new { registros, Name = "Unidad" }
    }.ToList();
    var a = list;
}

But it only return one object with all register inside it. What am I doing wrong? How can I create list of first item of all objects?

Upvotes: 1

Views: 875

Answers (2)

Uwe Keim
Uwe Keim

Reputation: 40726

How about using LINQ:

var s =
    registros
        .Select( r => r?.FirstOrDefault() )
        .Where( r => r != null )
        .ToList();

  • Line 3 iterates over all List items and selects the first (if available) or null otherwise.

  • Line 4 removes those that are null.

  • Line 5 converts to a List.

Here is a .NET Fiddle of the above code.

Responding to your comment below, here is how to rename items in the list, without selecting:

foreach ( var list in registros )
{
    if ( list != null && list.Length > 0 )
    {
        list[0] = "Unidad";
    }
}

And a .NET Fiddle for it.

Upvotes: 1

Oleg Varlamov
Oleg Varlamov

Reputation: 145

I propose to do it in this way using LINQ:

List<string[]> registros = GetRegistros();
var onlyFirstInEach = registros.SelectMany(x => x.Take(1)).ToList();

Upvotes: 1

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