Check if one list contains any elements from another

Question

I am just trying to return true if one list contains any of the Name/Value from list2:

This would be my structure:

public class TStockFilterAttributes
{
    public String Name { get; set; }
    public String Value { get; set; }
}

List<TStockFilterAttributes> List1 = new List<TStockFilterAttributes>();
List<TStockFilterAttributes> List2 = new List<TStockFilterAttributes>();

This should return true:

List1.Add(new TStockFilterAttributes { Name = "Foo", Value = "Bar" });
List2.Add(new TStockFilterAttributes { Name = "Foo", Value = "Bar" });

But this would return false because Name && Value don't match:

List1.Add(new TStockFilterAttributes { Name = "Foo", Value = "Bar" });
List2.Add(new TStockFilterAttributes { Name = "Foo", Value = "Foo" });

Each list could contains lots of different values and I just need to know if any one of List1 matches any one in List2.

I have tried using:

return List1.Intersect(List2).Any();

but this seems to return false in all cases, I am assuming this is because I am holding a class in List rather than a simple int / string?

Answer 1

Override Equals and GetHashCode implementation for your class:

public class TStockFilterAttributes
{
    public String Name { get; set; }
    public String Value { get; set; }

    public override bool Equals(object obj)
    {
        TStockFilterAttributes other = obj as TStockFilterAttributes;
        if (obj == null)
            return false;

        return Name == obj.Name && Value == obj.Value;
    }

    public override int GetHashCode()
    {
        return Name.GetHashCode() ^ Value.GetHashCode();
    }
}

Or provide a comparer to Intersect function.