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How to loop through all enum values in C#?

Below are the main ways to loop through all values in a C# enum, along with some tips and best practices.

Using Enum.GetValues()

A common approach is to call Enum.GetValues() on the enum type:

public enum Colors
{
    Red,
    Green,
    Blue
}

public void PrintAllColors()
{
    foreach (Colors color in Enum.GetValues(typeof(Colors)))
    {
        Console.WriteLine(color);
    }
}

  • How it Works:
    Enum.GetValues(typeof(Colors)) returns an Array of the defined values. In this case, it will yield Colors.Red, Colors.Green, and Colors.Blue.

  • Casting:
    The returned values are of type object, so you cast them back to the enum type ((Colors)) if you need strongly typed access.

Converting to a List or Array

Sometimes you want a strongly typed array or list for further processing:

var allColorsArray = (Colors[])Enum.GetValues(typeof(Colors));
var allColorsList = new List<Colors>(allColorsArray);

foreach (var color in allColorsList)
{
    Console.WriteLine(color);
}
  • Why Convert:
    It can be useful to store or filter these values later in your code.

Practical Uses

  • Populate UI Controls: For instance, filling a dropdown or combo box with enum values.
  • Switch Case Testing: Iterating over all possible enum values to ensure coverage in test scenarios.
  • Logging or Debugging: Printing out or inspecting all possible states.

Best Practices

  1. Define Meaningful Names: Enums are easiest to iterate over and understand when they have descriptive names (e.g., DaysOfWeek.Monday, DaysOfWeek.Tuesday, etc.).
  2. Avoid Changing Underlying Values: If you explicitly set numeric values, be consistent and don’t reorder them—this can lead to confusion when iterating.
  3. [Flags] Enums: For enums marked with [Flags], iterating over individual values might need special consideration since a single variable can contain multiple combined flags.

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In short, Enum.GetValues() is the go-to method for enumerating all enum values in C#. Whether you store them in a list, display them to a user, or test them in your code, the approach remains simple, idiomatic, and efficient.

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