Compare two Lists and pass to another-CodePudding

I have two List<Int64> ListA contains 10 digits of integer value and ListB contains 6 digits of integer, I have to compare both lists and pass to another List<int64> if ListA contains 6 digits from ListB.

CodePudding user response：

public static void Main(string[] args)
{
    var listA = new List<long>
    {
        1, 2, 3, 4, 5, 6
    };
    var listB = new List<long>
    {
        1, 2, 3, 4, 5, 6, 7, 8, 9, 10
    };

    bool doesListBContainListA = listA.All(numA => listB.Contains(numA));
    var listNew = new List<long>();
    if (doesListBContainListA)
    {
        listNew.AddRange(listA);
        listNew.AddRange(listB);
    }

    Console.WriteLine(string.Join(", ", listNew));
}

The above code will compare if all digits/numbers from listA are contained in listB and if they are they will be added to the new list.

P.S. long is the same as Int64

CodePudding user response：

Seems to me like you should be using linq's Intersect method:

var listA = new List<long> {0,1,2,3,4,5,6,7,8,9};
var listB = new List<long> {0,2,4,6,8};
var numbersInBoth = listA.Intersect(listB).ToList();

The numbersInBoth variable will be an instance of List<long> that contains only the numbers that both lists have.