Merge and Update Two Lists in C#

Question

I have two List objects:

For example:

List 1:
ID, Value where Id is populated and value is blank and it contains s

Answer 1

I would probably use a dictionary rather than a list:

    // sample data
    var original = new Dictionary();
    for (int i = 1; i <= 10; i++)
    {
        original.Add(i, null);
    }
    var updated = new Dictionary();
    updated.Add(2, 67);
    updated.Add(4, 90);
    updated.Add(5, 98);
    updated.Add(11, 20); // add

    // merge
    foreach (var pair in updated)
    {
        original[pair.Key] = pair.Value;
    }

    // show results
    foreach (var pair in original.OrderBy(x => x.Key))
    {
        Console.WriteLine(pair.Key + ": " + pair.Value);
    }

If you are talking about properties of an object, it will be trickier, but still doable.