Enitity Framework Multiple Rows Update Example in ASP.Net

I have the following Table

And below is how I'll update the Cities of Contacts with Id 1 and 2

        ContactsDBEntities contactsDB = new ContactsDBEntities();
        
        //Create a List of the Entity class and insert records to be updated
        List<Contact> contacts = new List<Contact> ();
       contacts.Add(new Contact
        {
            ContactId = 1,
            City = "Pune",
        });
        contacts.Add(new Contact
        {
           ContactId = 2,
            City = "Chicago",
        });
        foreach (Contact c in contacts)
        {
            Contact contact = contactsDB.Contacts.Single(i => i.ContactId == c.ContactId);
            contact.City = c.City;
            contactsDB.SaveChanges();
        }