Cast object to int[]-CodePudding

I have a array (with type of Object) which I'm extracting from a System.Collections.ArrayList. And I'm now trying to cast this object to a int[] so i can use it to compare it with another int[].

Note: I'm currently using .Net Framework 7.0.0

var query = (from el in l
                     where el.ID_Seal_From != "" && el.ID_Seal_From != null
                     select new
                     {
                         conn = el.Conn_from,
                         seal = el.ID_Seal_From
                     }).ToList();


        var query2 = (from el in l
                      where el.ID_Seal_To != "" && el.ID_Seal_To != null
                      select new
                      {
                          conn = el.Conn_to,
                          seal = el.ID_Seal_To
                      }).ToList();

        var res = query.Concat(query2).ToList();
        
        
        ArrayList arrLi = new();
        List<int> indexOfEqualElements = new();
        for (int i = 0; i < res.Count; i  )
        {
            for (int j = 0; j < res.Count; j  )
            {
                if (res[i].seal.CompareTo(res[j].seal) == 0)
                {
                    indexOfEqualElements.Add(j);
                }
            }

            if (Contains(arrLi, indexOfEqualElements.ToArray()) == -1) //to avoid multiple entries
            {
                arrLi.Add(indexOfEqualElements.ToArray());
            }
            indexOfEqualElements.Clear();
        }

In the "contains" call I'm trying to compare the Elements. For this case i need to avoid, that two equal arrays get added to the list. Because afterwards i need this distinct dataset to continue

CodePudding user response：

I'm sorry for not trying to understand all the code above, but you simply can cast all the values of an ArrayList to an IEnumerable like this:

var arrayList = new ArrayList(2)
{
    1,
    2
};

var integerEnumerable = arrayList
    .Cast<int>();

Feel free to add an .ToArray(), if you like an int[] instead.

CodePudding user response：

ArrayList is deprecated. If you wanted a list you should use List<int>. In this instance, it seems you actually need something like a HashSet<int>.

But to just get distinct elements you can simply use DistinctBy.

var query = (
    from el in l
    where el.ID_Seal_From != "" && el.ID_Seal_From != null
    select new
    {
        conn = el.Conn_from,
        seal = el.ID_Seal_From
    });

var query2 = (
    from el in l
    where el.ID_Seal_To != "" && el.ID_Seal_To != null
    select new
    {
        conn = el.Conn_to,
        seal = el.ID_Seal_To
    });

var res = query.Concat(query2).DistinctBy(el => el.seal);