CODEWITHSUNDEEP
c#.netlinq
inside
inside

Reputation: 3177

Change value of each item of string inside the list inside the list

Let's say I have a class Dad which has list of kids: 

public class Dad
{
    public List<Kid> kids = new List<Kid>();;
}

Each of those kids has a toy: 

public class Kid
{
    public List<string> Toys = new List<string>();
}

and as a sample I have collection of dads: 

Dad d1 = new Dad();
Kid k1 = new Kid();
k1.Toys.Add("toy1");
k1.Toys.Add("toy2");
d1.Kids.Add(k1);
List<Dad> dads = new List<Dad> { d1 };

I am trying to understand how to perform LINQ of List of Dads to change each kid's toy name to upper case.

Something like: 

var dadsWithKidsWithChangeToysName = dads.Select(dad => dad.Kids.Select(kid => kid.Toys.ForEach(toy => toy.ToUpper())));

Upvotes: 1

Views: 103

Answers (2)

Bruno
Bruno

Reputation: 4665

If your classes have a constructor accepting an IEnumerable, you could get it like so :

    public class Dad
    {
        public List<Kid> kids = new List<Kid>();

        public Dad(IEnumerable<Kid> kids)
        {
            this.kids = kids.ToList();
        }
    }
    public class Kid
    {
        public List<string> Toys = new List<string>();

        public Kid(IEnumerable<string> toys)
        {
            Toys = toys.ToList();
        }
    }

    var dads = new List<Dad> {
        new Dad(new [] { new Kid(new [] { "a", "b" }) }),
        new Dad(new [] { new Kid(new [] { "c", "d" }) }),
    };

    var dadsWithKidsWithChangeToysName = dads.Select(d => new Dad(d.kids.Select(k => new Kid(k.Toys.Select(t => t.ToUpper())))));

Upvotes: 1

Habib
Habib

Reputation: 223267

LINQ is for query, It is not for modification. You shouldn't use it for modification. Instead use a simple iteration (foreach/for) etc.

You can use LINQ to create a new List of Dad based on your existing list like:

var modifiedDads = dads.Select(d => new Dad()
{
    Kids = d.Kids.Select
        (
            k => new Kid()
            {
                Toys = k.Toys.Select(t => t != null ? t.ToUpper() : t).ToList()
            }
        ).ToList()
}).ToList();

Upvotes: 3

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