Multiple ways to Iterate Dictionary in C# Examples

In C#, a dictionary is a data structure that stores key-value pairs. This tutorial provides multiple examples of iterating through a dictionary object in C#.

C# Iterate dictionary examples

There are multiple ways to iterate key and value pairs

using forEach.

Iterate keys and values using foreach.

Each iteration holds an object and an object contains a key and value pair

foreach(var item in employees) {
      Console.WriteLine(item.Key + ": " + item.Value);

    }

You can also use typed object KeyValuePair<> generics to hold the key and value pair of a given type

//Iterate each object with KeyValuePair
foreach(KeyValuePair<int, string> item in employees){

        Console.WriteLine(item.Key+": "+item.Value);
}

Another way is to use destructing syntax, which works in .Net 4.7 version onwards.

foreach (var (key, value) in employees) {
        Console.WriteLine(key+": "+value);

}

Here is a complete example

using System;
using System.Collections.Generic;

public class Program {
  public static void Main() {
    Dictionary < int, string > employees = new Dictionary < int, string > ();
    employees.Add(1, "one");
    employees.Add(2, "four");
    employees.Add(3, "two");
    employees.Add(4, "three");
    // Iterate each object
    foreach(var item in employees) {
      Console.WriteLine(item.Key + ": " + item.Value);

    }
    //Iterate each object with KeyValuePair
    foreach(KeyValuePair<int, string> item in employees)
    {

        Console.WriteLine(item.Key+": "+item.Value);
    }

  }
}

use Dictionary.Values to iterate only values use Dictionary.Keys to iterate only keys.

Here is an example

// Iterate only Values
foreach(var item in employees.Values) {
      Console.WriteLine(item);

}
// Iterate only Keys
foreach(var item in employees.Keys) {
      Console.WriteLine(item);

}

Using LINQ
In LINQ, one can convert a dictionary object into a list of KeyValuePairs using the ToList() method. This method returns a list of KeyValuePairs, allowing for easier iteration over each object.
```
foreach (var item in dictionary.ToList())
{
        Console.WriteLine(item.Key+": "+item.Value);
}
```
This approach has several advantages
- It is useful for modifying data while iterating.
- Since the dictionary is converted to a list, the list preserves the insertion order.
Parallel.ForEach function This is another of iterating dictionary concurrently using parallel technique in multiple threads.
It iterates each item using parallel.ForEach function. item is of type KeyValuePair type
```
Parallel.ForEach(dictionary, item =>
{
          Console.WriteLine(item.Key+": "+item.Value);
});
```

Conclusion

You learned multiple ways to iterate Dictionary in C#

Multiple ways to Iterate Dictionary in C# Examples

#C# Iterate dictionary examples

#Conclusion

C# Iterate dictionary examples

Conclusion