JSON (JavaScript Object Notation) is a human-readable data interchange format which is based on collection of name/value pairs and ordered list of values. These days, Due to more use of AJAX and client side scripting, JSON is widely used to interact with the server as request response format.

To check JSON response of different .NET objects, The following method is used to serialize object :

public string GetJSON(object obj){
        System.Web.Script.Serialization.JavaScriptSerializer oSerializer =
            new System.Web.Script.Serialization.JavaScriptSerializer();
        return oSerializer.Serialize(obj);
    }

Array:

int[] oList = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
Label1.Text = GetJSON(oList);  

Output:

[5,4,1,3,9,8,6,7,2,0]

Note: Don't confuse with C# declaration and JSON output.In C# we are using curely braces{} and getting big braces [] in JSON output.

Now see following 2d array:

string[,] oList = new string[,] { {"Col 1 Row 1 ","Col 2 Row 1"},{"Col 1 Row 2","Col 2 Row 2"}}; 
Label1.Text = GetJSON(oList);  

Don't expect to get 2d Array in JSON, you will get same array.

Output:

["Col 1 Row 1 ","Col 2 Row 1","Col 1 Row 2","Col 2 Row 2"]

Dictionary:

 IDictionary<string, string> oDict = new Dictionary<string, string>();
        oDict.Add("Key1", "Value1");
        oDict.Add("Key2", "Value2");
        oDict.Add("Key3", "Value3");
        oDict.Add("Key4", "Value4");
        oDict.Add("Key5", "Value5");
        Label1.Text = GetJSON(oDict);

Output:

{"Key1":"Value1","Key2":"Value2","Key3":"Value3","Key4":"Value4","Key5":"Value5"}

You will get object having key value pairs.

NameValueCollection:

NameValueCollection oList = new NameValueCollection();
        oList.Add("Key1", "Value1");
        oList.Add("Key2", "Value2");
        oList.Add("Key3", "Value3");
        oList.Add("Key4", "Value4");
        oList.Add("Key5", "Value5");
        Label1.Text = GetJSON(oList);

Output:

["Key1","Key2","Key3","Key4","Key5"]

You will get array of all keys.

Stack:

Stack stackObject = new Stack();
        stackObject.Push("First");
        stackObject.Push("Second");
        stackObject.Push("Third");
        Label1.Text = GetJSON(stackObject);  

Output:

["Third","Second","First"]

You will get array having elements in reverse order.

Queue:

Queue queueObject = new Queue();
        queueObject.Enqueue("First");
        queueObject.Enqueue("Second");
        queueObject.Enqueue("Third");
        Label1.Text = GetJSON(queueObject); 

Output:

["First","Second","Third"]

Generic List:

public struct Person
    {
        public string Name { get; set; }
        public string Age { get; set; }
        public string ID { get; set; }
    }
Person oEmployee1 = new Person { Name = "Pini", ID = "111", Age = "30" };
        Person oEmployee2 = new Person { Name = "Yaniv", ID = "Cohen", Age = "31" };
        Person oEmployee3 = new Person { Name = "Yoni", ID = "Biton" };
        List<Person> oList = new List<Person>() { oEmployee1, oEmployee2, oEmployee3 };
        Label1.Text = GetJSON(oList);  

Output:

[{"Name":"Pini","Age":"30","ID":"111"},{"Name":"Yaniv","Age":"31","ID":"Cohen"},{"Name":"Yoni","Age":null,"ID":"Biton"}]

In above example, Person structure is created and different objects are added in List of Person. You will get array of objects in JSON. In oEmployee3, Age is not defined. So, you will get null in output.

ArrayList:

ArrayList oList = new ArrayList { oEmployee1, oEmployee2, stackObject, queueObject, oDict };        
        Label1.Text = GetJSON(oList);  

Output:

[{"Name":"Pini","Age":"30","ID":"111"},{"Name":"Yaniv","Age":"31","ID":"Cohen"},["Third","Second","First"],["First","Second","Third"],{"Key1":"Value1","Key2":"

Value2","Key3":"Value3","Key4":"Value4","Key5":"Value5"}]

Anonymous types:

 DataTable oList1 = GetDataTable();
        var oList = from t in oList1.AsEnumerable()
                    select new { Name = t.Field<string>("Name"), Amt = t.Field<string>("Amount") };
        Label1.Text = GetJSON(oList);

Output:

[{"Name":"NAME-0","Amt":"0"},{"Name":"NAME-1","Amt":"10"},{"Name":"NAME-1","Amt":"30"},{"Name":"NAME-0","Amt":"40"}]

In above code, the two columns (Name and Amount) are selected from Datatable and you will get Array of objects having Name and Amount parameters.

Hope, It helps.