CODEWITHSUNDEEP
c#listreturn-value
Len Rinzler
Len Rinzler

Reputation: 23

Return List With Multiple Elements

I'm struggling getting my head around returning a List that has multiple elements (PHP background - I'd use arrays for this in PHP).

I have a large string that I'm parsing in a WHILE loop. I want to return a List with pairs of elements. I've tried something like this:

static public List<string> getdata(string bigfile)
{
var data = new List<string>[] { new List<string>(), new List<string>() };  // create list to hold data pairs

While (some stuff)
{
   // add element pair to List<data>
   data[0].Add(this);  // add element to list - 'this' is declared and assigned (not shown)    
   data[1].Add(that);  // add element to list - 'that' is declared and assigned (not shown)

}

return data???;  // <<-- This is where I'm failing. I can, of course, return just one of the elements, like return data[0];, but I can't seem to get both elements (data[0] and data[1]) together.

}  // end getdata

I've reviewed some answers, but I'm missing something. I've tried several things syntactically for the return value, but no luck. Any help would be greatly appreciated. I hate asking questions, but I've spent some time on this and I'm just not finding what I want.

Upvotes: 1

Views: 364

Answers (4)

Damith
Damith

Reputation: 63065

try with 

static public List<string>[] getdata(string bigfile)
{
   ....
}

Or

But if you need to return list of string array, then change the method as 

static public List<string[]> getdata(string bigfile)
{
    List<string[]> data= new List<string[]>();

    While (some stuff)
    {
       data.Add(this);    
       data.Add(that); 

    }

    return data;
}

Upvotes: 0

Dennis
Dennis

Reputation: 37770

I want to return a List with pairs of elements

If you want pairs, use pairs:

static public List<Tuple<string, string>> getdata(string bigfile)
{
    var data = new List<Tuple<string, string>>(); // create list to hold data pairs

    while (some stuff)
    {
        // add element pair
        data.Add(Tuple.Create(a, b)); // 'a' is declared and assigned (not shown)    
                                      // 'b' is declared and assigned (not shown)
    }

    return data;
}

Upvotes: 0

Sajeetharan
Sajeetharan

Reputation: 222582

The problem there is you are returning a Collection of List so the return type is mismatching. Try this one,

            var data = new List<string>();

            while (some stuff)
            {

                data.Add("test0");
                data.Add("test1");
            }
            return data;

Upvotes: 0

Igor
Igor

Reputation: 15893

Change method declaration to:

static public List<string>[] getdata(string bigfile)

Upvotes: 2

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