Enum parsing from strings in C Sharp (C#) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an enum in C#?

An enum (short for enumeration) is a special data type that lets you define a set of named constants, making code easier to read and maintain.

beginner

How do you parse a string to an enum value in C#?

You use Enum.Parse(typeof(EnumType), stringValue) or Enum.TryParse<EnumType>(stringValue, out var result) to convert a string to an enum value.

intermediate

What is the difference between Enum.Parse and Enum.TryParse?

Enum.Parse throws an exception if parsing fails, while Enum.TryParse returns a boolean indicating success or failure without throwing exceptions.

intermediate

How can you make enum parsing case-insensitive?

Use the overload Enum.TryParse<EnumType>(stringValue, ignoreCase: true, out var result) to ignore case differences when parsing.

intermediate

What happens if you try to parse a string that is not a valid enum name?

Using Enum.Parse will throw a System.ArgumentException. Using Enum.TryParse will return false and set the output to the default enum value.

Which method safely parses a string to an enum without throwing exceptions?

A Enum.Parse

B Enum.TryParse

C Enum.ToString

D Enum.GetName

Enum.TryParse returns a boolean indicating success or failure and does not throw exceptions, making it safer for parsing.

How do you parse a string to an enum ignoring case differences?

A Enum.Parse without parameters

B Enum.Parse with ignoreCase parameter set to true

C Enum.TryParse with ignoreCase parameter set to true

D Enum.ToString with ignoreCase

Enum.TryParse<T>(stringValue, ignoreCase: true, out var result) allows case-insensitive parsing.

What exception does Enum.Parse throw if parsing fails?

A System.FormatException

B System.NullReferenceException

C System.InvalidOperationException

D System.ArgumentException

Enum.Parse throws System.ArgumentException when the string does not match any enum name.

What is the return type of Enum.TryParse?

A bool

B enum type

C void

D string

Enum.TryParse returns a boolean indicating whether parsing succeeded or failed.

Which of these is a valid way to parse a string to an enum value Color?

A Enum.TryParse<Color>("Red", out var color)

B Enum.Parse<Color>("Red")

C Color.Parse("Red")

D Enum.ToString("Red")

Enum.TryParse<Color>(string, out var) is the correct generic method to parse strings to enums safely.

Explain how to convert a string to an enum value in C# and handle invalid input safely.

Think about methods that avoid exceptions and how to check if parsing worked.

Describe the difference between Enum.Parse and Enum.TryParse when parsing strings to enums.

One method throws exceptions on failure, the other returns a success flag.