Check out example codes for "serialize collection c#". It will help you in understanding the concepts better.

Code Example 1

Product p1 = new Product
{
    Name = "Product 1",
    Price = 99.95m,
    ExpiryDate = new DateTime(2000, 12, 29, 0, 0, 0, DateTimeKind.Utc),
};
Product p2 = new Product
{
    Name = "Product 2",
    Price = 12.50m,
    ExpiryDate = new DateTime(2009, 7, 31, 0, 0, 0, DateTimeKind.Utc),
};

List<Product> products = new List<Product>();
products.Add(p1);
products.Add(p2);

string json = JsonConvert.SerializeObject(products, Formatting.Indented);
//[
//  {
//    "Name": "Product 1",
//    "ExpiryDate": "2000-12-29T00:00:00Z",
//    "Price": 99.95,
//    "Sizes": null
//  },
//  {
//    "Name": "Product 2",
//    "ExpiryDate": "2009-07-31T00:00:00Z",
//    "Price": 12.50,
//    "Sizes": null
//  }
//]

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