How to get the int value from an enum in C#

Simply type cast the enum to an int.

enum Side
{
   Left, 
   Right, 
   Top, 
   Bottom
}
    
int value = (int)Side.Left;

The above will work for the vast majority of enums as the default underlying type for an enum is int.

However, enums can have different underlying types. If an enum is declared as a uint, long, or ulong, it should be cast to the type of the enum. Here's an example for long:

enum Planet : long
{
   Mars = 137726861, 
   Jupiter = 2039382280, 
   Saturn = 2647483649 
}
    
long value = (long)Planet.Saturn;