2 ways to convert/cast int to enum in C#

There are 2 ways To convert or cast int to enum in C#

1. Using C# explicit type casting.
2. Using Enum.ToObject() method

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Solution 1: Using C# explicit type casting #

The simple way to convert int to enum in C# is to use explicit type casting.

Let’s go through an example to understand it further.

We have an enum type called LogLevel, which represents different levels of logging.

public enum LogLevel
{
   ERROR=1, 
   WARN=2, 
   INFO=3, 
   DEBUG=4
}

int logEnumInteger = 1;
LogLevel errorEnum = (LogLevel) logEnumInteger;
Console.WriteLine(errorEnum.ToString());//ERROR

Explicit casting done by placing the enum type in parentheses in front of the int value.

But there is a problem with above C# int to enum conversion.

What if the int value does not exists in the C# Enum variable?

int logEnumInteger = 100;
LogLevel unknownEnum = (LogLevel) logEnumInteger;
Console.WriteLine(unknownEnum.ToString());//100

It will not throw any exception.

So it’s better to check if the int value exists in C# Enum before casting it to the integer.

Check if an integer exists or not in C# enum variable #

To get the all integer values in C# Enum we can use Enum.GetValues method.

Convert them to C# list, so that we can use list.Contains() method to check if the given integer exist in enum variable.

var intValue = 100;
var enumValues = Enum.GetValues(typeof(LogLevel)).Cast<int>().ToList();

if(enumValues.Contains(intValue)){
   Console.WriteLine("We can Cast C# int to Enum");  
   LogLevel loggingValue = (LogLevel) intValue;
}else{
  Console.WriteLine("Cannot Cast C# int to Enum");
}

We can use Enum.IsDefined() method to check if converted integer value exist in the given enum type.

var enumValue = (LogLevel)1;

if (Enum.IsDefined(typeof(LogLevel), enumValue)){
   Console.WriteLine("The converted int to enum value is",enumValue);
}else{
   Console.WriteLine("Cannot Convert int to Enum",enumValue);
}

Solution 2: Use Enum.ToObject() method #

We can use C# Enum.ToObject() method, convert int value to enum in C#.

var enumValue = Enum.ToObject(typeof(LogLevel),1);

Console.WriteLine(enumValue);

//ERROR

Console.WriteLine(enumValue.GetType());
//LogLevel