Enum declaration syntax in C Sharp (C#) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an enum named Color.

C Sharp (C#)

enum [1] { Red, Green, Blue }

Drag options to blanks, or click blank then click option'

AColor

Bcolor

CColors

DcolorEnum

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase names for enums.

Using plural form when singular is expected.

The enum name should be Color to match the declaration.

2fill in blank

medium

Complete the code to specify the underlying type of the enum as byte.

C Sharp (C#)

enum Status : [1] { Active, Inactive, Pending }

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Aint

Bbyte

Cstring

Dbool

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-integral types like string or bool as underlying type.

Omitting the colon before the type.

The underlying type byte is specified after the colon in enum declaration.

3fill in blank

hard

Fix the error in the enum declaration by completing the code.

C Sharp (C#)

enum Days [1] Monday, Tuesday, Wednesday }

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A{

B(

C[

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses or brackets instead of braces.

Omitting braces entirely.

Enum members must be enclosed in curly braces { }.

4fill in blank

hard

Fill both blanks to declare an enum named Direction with underlying type short.

C Sharp (C#)

enum [1] : [2] { North, South, East, West }

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ADirection

Bshort

Cint

DCompass

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong underlying types like int when short is required.

Using incorrect enum names.

The enum name is Direction and the underlying type is short.

5fill in blank

hard

Fill all three blanks to declare an enum named Level with underlying type int and members Low, Medium, High.

C Sharp (C#)

enum [1] : [2] { [3] }

Drag options to blanks, or click blank then click option'

ALevel

Bint

CLow, Medium, High

DLevels

Attempts:

3 left

💡 Hint

Common Mistakes

Using plural enum names when singular is expected.

Omitting commas between enum members.

The enum is named Level, uses int as underlying type, and has members Low, Medium, High.

Practice

1. What is the purpose of an enum in C#?

easy

A. To group related named constants together

B. To create a new class type

C. To define a method

D. To declare a variable

Solution

1. Step 1: Understand enum concept

   An enum groups related named constants to make code clearer.

2. Step 2: Compare with other options

   Enums are not classes, methods, or variables but a special type for constants.

3. Final Answer:

   To group related named constants together -> Option A

4. Quick Check:

   Enum = group constants [OK]

Hint: Enums group named constants, not variables or methods [OK]

Common Mistakes:

• Thinking enum is a class
• Confusing enum with method or variable
• Assuming enum holds variable data

2. Which of the following is the correct syntax to declare an enum named Days with members Monday and Tuesday?

easy

A. enum Days: Monday, Tuesday;

B. enum Days = { Monday, Tuesday };

C. enum Days { Monday, Tuesday };

D. enum Days (Monday, Tuesday);

Solution

1. Step 1: Recall enum declaration syntax

   Enums use curly braces with members separated by commas, no equals or parentheses.

2. Step 2: Check each option

   enum Days { Monday, Tuesday }; matches correct syntax: enum Days { Monday, Tuesday };.

3. Final Answer:

   enum Days { Monday, Tuesday }; -> Option C

4. Quick Check:

   Enum syntax uses braces and commas [OK]

Hint: Use braces and commas for enum members [OK]

Common Mistakes:

• Using equals sign (=) after enum name
• Using parentheses instead of braces
• Using colon (:) instead of opening brace

3. What is the output of this code?

enum Color { Red, Green, Blue };
Console.WriteLine((int)Color.Green);

medium

A. 0

B. 1

C. 2

D. Green

Solution

1. Step 1: Understand default enum values

   Enum members start at 0 by default: Red=0, Green=1, Blue=2.

2. Step 2: Cast enum member to int

   Printing (int)Color.Green outputs its numeric value 1.

3. Final Answer:

   1 -> Option B

4. Quick Check:

   Green = 1 by default [OK]

Hint: Enum members start at 0 unless assigned [OK]

Common Mistakes:

• Assuming first member starts at 1
• Printing enum name instead of int value
• Confusing enum member order

4. Identify the error in this enum declaration:

enum Status
{
  Started = 1,
  InProgress = 2,
  Completed = "Done"
};

medium

A. Enum members must be separated by semicolons

B. Missing semicolon after enum declaration

C. Enum name must be lowercase

D. Enum members cannot have string values

Solution

1. Step 1: Check enum member value types

   Enum members must be integral types (int, byte, etc.), not strings.

2. Step 2: Analyze the given code

   "Completed = \"Done\"" assigns a string, which is invalid.

3. Final Answer:

   Enum members cannot have string values -> Option D

4. Quick Check:

   Enum values must be integers [OK]

Hint: Enum values must be integers, not strings [OK]

Common Mistakes:

• Assigning string values to enum members
• Thinking semicolon is required after enum
• Assuming enum names must be lowercase

5. How can you declare an enum Priority with members Low=1, Medium=5, and High=10 so that the values are not sequential?

hard

A. enum Priority { Low = 1, Medium = 5, High = 10 };

B. enum Priority { Low, Medium, High }

C. enum Priority { Low = 1; Medium = 5; High = 10 }

D. enum Priority = { Low = 1, Medium = 5, High = 10 }

Solution

1. Step 1: Assign explicit values to enum members

   To set custom values, assign each member an integer with = and commas between.

2. Step 2: Check syntax correctness

   enum Priority { Low = 1, Medium = 5, High = 10 }; uses correct syntax with commas and explicit values.

3. Final Answer:

   enum Priority { Low = 1, Medium = 5, High = 10 }; -> Option A

4. Quick Check:

   Use = and commas for custom enum values [OK]

Hint: Assign values with = and separate members by commas [OK]

Common Mistakes:

• Using semicolons instead of commas
• Omitting explicit values for custom numbers
• Using equals sign after enum name