How To Play With Enum in C#

Lajapathy Arun

7y488.4k14100Article

EnumerationC# enum

14 Comments

Join the conversation! Your thoughts help the community grow.

Cipher Coder6y ago
Good one ...
Vihaan R6y ago
Hi thank you for sharing! Very informative tutorial. If you would like to see more I encourage you to view as it is helpful. Thanks! You can check it out here: https://systemoutofmemory.com/blogs/the-programmer-blog/c-sharp-cast-int-to-enum
Rajeesh Menoth11y ago
Good one
Mohamed Yunus11y ago
Well try Arun
nikhil sreeni13y ago
Thanks for the post,Its really helpful
Nagashyam Kumar14y ago
Good One
- Lajapathy Arun14y ago
  1.Enums are not allocated in memory 2.They exist only on compilation stage. When code runs - there is no enums there anymore. 3. There is no runtime work.Reduces the chance of bug. IF you use Dictionary or Array, then it allocates memory. How much memory you reducing it helps when huge of hits to the page. Not an Best practice to the real application. Just you read the comment given previously to "AMit". There are several Used are there of using
- Lajapathy Arun14y ago
  This is the First article so i am happy to see comments. Thanks Friend
- Selvambika T14y ago
  Hi Arun, Am a junior developer I just want to know the following: How the enum differs from obtaining values from Dictionary using a key? Also we can take the values in array using the index. May I know the advantage of this enum here?
Amit Maheshwari14y ago
It's a very well explanation about the enum keep it up. But I want to know that where we can use it please tell me? And why we used it?
- Lajapathy Arun14y ago
  http://www.c-sharpcorner.com/Blogs/8589/advantage-of-using-enum-in-real-life-situation.aspx
- Lajapathy Arun14y agoedited
  Thanks Amit, Just your comment is the first one that excited me as a beginner level in publishing article. Answer to Your Question: 1.If you Writing the Architectural Code, then You have to go for Enum not Const variable String like 'const sting Word="Word"'<br/> 2. In my example i have used the MS product like Word,Excel etc , it clearly tells you, that You have definite choice of list in the application, not more than that. 3. One more, if new person wants to add a new product, he clearly knows where to add this product and how it can be used. 4.Enum.Parse() , this is very useful, if you consider the web application if the query string "product=word" in the URL, then we use to Get enum and use throughout the Application , it helps others. 5. Main thing is Readability , this is main one you should always remember this. 6.Enum.Parse throws error if value is not correct, so we use Enum.IsDefined to check. So every helper method in Enum helps a alot. 7. If you have choice like list of action or options or possibilities , then you can go for enum. eg.,FileAccess(Read,Write etc). 6. You will get error in compile time itself not run time, it is better and best practice. 7. As you know it is a value type and also we can customize the Enum value as mentioned in this article. 8. It reduces the chance of Bug in code something like case sensitive problem. 9. Intellience makes you happy to work as you know how much it is helful if Enum used. This is also best use of Enum. once place of code we use Word , in other place we use word, it is inconsistent too. If you think of it, it helps a lot. Summary: list of action or options or possibilities we can use then best practice is always enum. Thanks Lajapathy Arun
- Lajapathy Arun14y ago
  I have given as points whatever i have faced in my real life while coding. I hope it helps you. Please let me know if you have anything.

In this article, you will see use of enum type variables in C#.

Sample enum variables to use:

internal enum MicrosoftOffice
{
Word = 0,
Excel = 1,
Powerpoint = 3,
Visio = 5
}

How to get enum variable name by its value in C#?

Retrieves the name of the constant in the specified enumeration that has the specified value.

/// This is used to get Enum name by its value as integer.
private static void GetEnumName()
{
int[] enumValues = new int[] { 0, 1, 3, 5 };
foreach (int enumValue in enumValues)
{
Console.WriteLine(Enum.GetName(typeof(MicrosoftOffice), enumValue));
}
Console.ReadKey();
}

Output

How to iterate an enum variable or enum name in C#?

Retrieves an array of the names of the constants in a specified enumeration.

/// This is used to iterate enum variables.
private static void IterateEnumVariables()
{
Console.WriteLine("List of Enums");
string[] officenames = Enum.GetNames(typeof(MicrosoftOffice));
foreach (string officename in officenames)
{
Console.WriteLine(officename);
}
Console.ReadKey();
}

Output

How to get enum variable name by its value in C#?

Retrieves an array of the values of the constants in a specified enumeration.

///This is used to get Enum values as array.
private static void GetEnumValues()
{
Array enumValueArray = Enum.GetValues(typeof(MicrosoftOffice));
foreach (int enumValue in enumValueArray)
{
Console.WriteLine("Name: " + Enum.GetName(typeof(MicrosoftOffice), enumValue) + " , Value: " + enumValue);
}
Console.ReadKey();
}

Output

How to convert an enum to a String in C#?

ToString() converts Enum to string.

/// This is used to convert Enum to string.
private static void EnumToString()
{
Console.WriteLine("Converting Enum to String");
Console.WriteLine(MicrosoftOffice.Powerpoint.ToString());
Console.WriteLine(MicrosoftOffice.Word.ToString())
Console.ReadKey();
}

Output

How to convert a String to an enum or Parse in C#?

Converts the string representation of the name or numeric value of one or more enumerated constants to an equivalent enumerated object.

/// <summary>
/// This is used to convert string to Enum variable.
/// </summary>
private static void ParseEnum()
{
MicrosoftOffice ms = (MicrosoftOffice)Enum.Parse(typeof(MicrosoftOffice), "Word");
Console.WriteLine(ms.ToString());
MicrosoftOffice ms1 = (MicrosoftOffice)Enum.Parse(typeof(MicrosoftOffice), "Excel");
Console.WriteLine(ms1.ToString());
Console.ReadKey();
}

Output

How to check and Parse a String from the enum variable using C#?

Converts the string representation of the name or numeric value of one or more enumerated constants to an equivalent enumerated object. The return value indicates whether the conversion succeeded.

It is optionally case sensitive; you can just specify true or false to specify the option.

/// <summary>
/// This is used to check and get value of specified string.
/// </summary>
private static void TryParseEnum()
{
MicrosoftOffice msDefault = MicrosoftOffice.Powerpoint;
//Supplying correct enum string.
bool ms = Enum.TryParse("Word", true, out msDefault);
Console.WriteLine(ms.ToString() + " " + msDefault.ToString());
MicrosoftOffice msDefault1 = MicrosoftOffice.Powerpoint;
//Supplying wrong enum string.
bool ms1 = Enum.TryParse("excl", out msDefault1);
Console.WriteLine(ms1.ToString() + " " + msDefault1.ToString());
Console.ReadKey();
}

Output

How to check whether the passed enum exists or not using C#?

Indicates whether a constant with a specified value exists in a specified enumeration.

/// This is used to check whether the enum is available in Enum type.
private static void EnumIsDefined()
{
if (Enum.IsDefined(typeof(MicrosoftOffice), "Word"))
{
Console.WriteLine("Word Enum Exists");
}
if (Enum.IsDefined(typeof(MicrosoftOffice), "Excl"))
{
Console.WriteLine("Excel Enum Exists");
}
else
{
Console.WriteLine("Enum Not Exists");
}
Console.ReadKey();
}

Output

How to create a Custom String value from an enum variable and how to use it?

This is used to set the Custom string to the enum variable as an attribute and get the value at runtime.

Here we can use any custom string to the enum variable so that it is very handy to use this custom string.

Steps to follow

First create a sample set of enum variables.
Then, create a custom attribute class for just custom String Value.
Create an extension method for just enum.
Use the extension method to get just enum custom string value.

1. Enum variable for custom String value in C#:

internal enum MicrosoftOfficeString : int
{
[EnumStringAttribute("Microsoft Word")]
Word = 0,
[EnumStringAttribute("Microsoft Excel")]
Excel = 1,
[EnumStringAttribute("Microsoft Powerpoint")]
Powerpoint = 3,
[EnumStringAttribute("Microsoft Visio")]
Visio = 5
}

2. How to create a custom attribute for a custom string value in C#?

public class EnumStringAttribute : Attribute
{
public EnumStringAttribute(string stringValue)
{
this.stringValue = stringValue;
}
private string stringValue;
public string StringValue
{
get { return stringValue; }
set { stringValue = value; }
}
}

3. How to create an extension method for an enum custom String?

public static class ExtenstionClass
{
public static string GetStringValue(this Enum value)
{
Type type = value.GetType();
FieldInfo fieldInfo = type.GetField(value.ToString());
// Get the stringvalue attributes
EnumStringAttribute[] attribs = fieldInfo.GetCustomAttributes(
typeof(EnumStringAttribute), false) as EnumStringAttribute[];
// Return the first if there was a match.
return attribs.Length > 0 ? attribs[0].StringValue : null;
}
}

4. How to get a custom String value from an enum variable using attribute in C#?

/// This is used to get the Cutom Attribute.
/// </summary>
private static void GetEnumCustomAttributeString()
{
//This return the custom attribute string value.
Console.WriteLine(MicrosoftOfficeString.Excel.GetStringValue());
Console.WriteLine(Environment.NewLine);
string[] officenames = Enum.GetNames(typeof(MicrosoftOffice));
foreach (string officename in officenames)
{
MicrosoftOfficeString ms = (MicrosoftOfficeString)Enum.Parse(typeof(MicrosoftOfficeString), officename);
//This return the custom attribute string value.
Console.WriteLine(ms.GetStringValue());
}
Console.ReadKey();
}

Output