Looping through dictionary object

Question

I am very new to .NET, used to working in PHP. I need to iterate via foreach through a dictionary of objects. My setup is an MVC4 app.

The Model looks l

Answer 1

One way is to loop through the keys of the dictionary, which I recommend:

foreach(int key in sp.Keys)
    dynamic value = sp[key];

Another way, is to loop through the dictionary as a sequence of pairs:

foreach(KeyValuePair<int, dynamic> pair in sp)
{
    int key = pair.Key;
    dynamic value = pair.Value;
}

I recommend the first approach, because you can have more control over the order of items retrieved if you decorate the Keys property with proper LINQ statements, e.g., sp.Keys.OrderBy(x => x) helps you retrieve the items in ascending order of the key. Note that Dictionary uses a hash table data structure internally, therefore if you use the second method the order of items is not easily predictable.

Update (01 Dec 2016): replaced vars with actual types to make the answer more clear.

Answer 2

public class TestModels
{
    public Dictionary<int, dynamic> sp = new Dictionary<int, dynamic>();

    public TestModels()
    {
        sp.Add(0, new {name="Test One", age=5});
        sp.Add(1, new {name="Test Two", age=7});
    }
}

Answer 3

You can do it like this.

Models.TestModels obj = new Models.TestModels();
foreach (var item in obj.sp)
{
    Console.Write(item.Key);
    Console.Write(item.Value.name);
    Console.Write(item.Value.age);
}

The problem you most likely have right now is that the collection is private. If you add public to the beginning of this line

Dictionary<int, dynamic> sp = new Dictionary<int, dynamic> 

You should be able to access it from the function inside your controller.

Edit: Adding functional example of the full TestModels implementation.

Your TestModels class should look something like this.

public class TestModels
{
    public Dictionary<int, dynamic> sp = new Dictionary<int, dynamic>();

    public TestModels()
    {
        sp.Add(0, new {name="Test One", age=5});
        sp.Add(1, new {name="Test Two", age=7});
    }
}

You probably want to read up on the dynamic keyword as well.

Answer 4

It depends on what you are after in the Dictionary

Models.TestModels obj = new Models.TestModels();

foreach (var keyValuPair in obj.sp)
{
    // KeyValuePair<int, dynamic>
}

foreach (var key in obj.sp.Keys)
{
     // Int 
}

foreach (var value in obj.sp.Values)
{
    // dynamic
}