Using .Zip or linq in c # to add two fields from a series of objects contained in two lists

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Using .Zip or linq in c # to add two fields from a series of objects contained in two lists

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#1 by (1 votes)
#2 by (1 votes)

2

I have a list of objects

List<Objeto> lista1;
List<Objeto> lista1;

Object has an attribute X and an attribute Y .

I want to do the following:

List<Objeto> listaSuma => add the values Y of each object and return this to the new list of objects ( objeto { X , Y + Y) ).

Obviously with a for loop I've already done it. I want to use Linq or Zip , but I do not know how.

PD (objects have more variables, but you do not have to do anything with them)

List<Coordenadas> result = new List<Coordenadas>();
for (int i = 0; i < list1.Count; i++)
  {
     objetAux = new Coordenadas();
     objetAux.Y = list1[i].Y + list12[i].Y;
     objetAux.X = list1[i].X;
     result.Add(objetAux);
  }

c# linq lambda

asked by Jesús Álvarez 11.01.2017 в 15:17

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2 answers

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score 1 · Answer 1

Indeed, you can use Zip() to combine both lists with the desired result:

List<Coordenadas> result = 
    list1.Zip(
        list12,
        (primero, segundo) =>
            new Coordenadas
            {
                Y = primero.Y + segundo.Y,
                X = primero.X
            }).ToList();

Although the syntax is interesting, do not expect the performance to be better than the loop you already have.

score 1 · Answer 2

If I understand you correctly, all you have to do is select by generating each object as you want, something like this:

List<objeto> listaSuma = lista1.Select(l => new objeto() { x=l.x, y=l.y + l.y })
                              .ToList<objeto>();

Edit

As you comment that objeto has more properties, probably what you need is a list using a new anonymous type. This would be the code:

var listaSuma = lista1.Select(l => new { x=l.x, y=l.y + l.y }).ToList();

Edit 2

In your initial question I did not really understand what you wanted. If what you need is to join the two lists, you can effectively use Zip (from Net 4.0) and do the following:

var listaSuma  = lista1.Zip(lista2, (primero, segundo) => 
                          new { x = primero.x, y = primero.y + segundo.y }).ToList();