Assign null values to properties inside Generic list using Linq query in C#

Hi Kumas1281,

Refer below code.

protected void Page_Load(object sender, EventArgs e)
{
    List<OrganizationList> organizationList = new List<OrganizationList>();
    organizationList.Add(new OrganizationList { OrganizationLevel = 0, NetworkParticipation = "Test 1", ApprovalPolicyID = 1, LastUpdateDate = DateTime.Now });
    organizationList.Add(new OrganizationList { OrganizationLevel = 0, NetworkParticipation = "Test 2", ApprovalPolicyID = 2, LastUpdateDate = DateTime.Now });
    organizationList.Add(new OrganizationList { OrganizationLevel = 1, NetworkParticipation = "Test 3", ApprovalPolicyID = 3, LastUpdateDate = DateTime.Now });
    organizationList.Add(new OrganizationList { OrganizationLevel = 2, NetworkParticipation = "Test 4", ApprovalPolicyID = 4, LastUpdateDate = DateTime.Now });
    organizationList.Add(new OrganizationList { OrganizationLevel = 0, NetworkParticipation = "Test 5", ApprovalPolicyID = 5, LastUpdateDate = DateTime.Now });
    organizationList.Add(new OrganizationList { OrganizationLevel = 1, NetworkParticipation = "Test 6", ApprovalPolicyID = 6, LastUpdateDate = DateTime.Now });
    if (organizationList.Count > 0)
    {
        var organizationList0 = organizationList.Where(x => x.OrganizationLevel == 0).FirstOrDefault();
        organizationList0.NetworkParticipation = null;
        organizationList0.ApprovalPolicyID = null;
        organizationList0.LastUpdateDate = null;
    }
}

public class OrganizationList
{
    public int OrganizationLevel { get; set; }
    public string NetworkParticipation { get; set; }
    public int? ApprovalPolicyID { get; set; }
    public DateTime? LastUpdateDate { get; set; }
}