Enum usage in C - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an enum in C?

An enum in C is a way to name a set of integer constants. It helps make code easier to read by giving meaningful names to numbers.

beginner

How do you define an enum for days of the week in C?

You write:

enum Day { Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday };

This creates names for numbers starting at 0.

intermediate

Can you assign specific numbers to enum members?

Yes. You can set values like

enum Color { Red = 1, Green = 5, Blue = 10 };

. Members without assigned values get the next number after the previous one.

beginner

How do you use an enum variable in C?

Declare a variable with the enum type, like

enum Day today;

. Then assign a value:

today = Monday;

. It stores the integer for Monday.

beginner

What is the default starting value of the first enum member if not assigned?

The first enum member starts at 0 by default. Each next member increases by 1 unless specified otherwise.

What value does the first member of an enum have if not explicitly assigned?

A -1

B 1

C 0

D Undefined

By default, the first enum member has the value 0.

How do you declare an enum variable named color of type enum Color?

A enum Color color;

B Color enum color;

C int color;

D var color = enum Color;

The correct syntax is enum Color color; to declare a variable of enum type.

If you define enum Fruit { Apple = 3, Banana, Cherry };, what is the value of Cherry?

A 3

B 5

C Undefined

D 4

Cherry gets the next integer after Banana, which is 5.

Which of these is a benefit of using enums?

A Automatically creates functions

B Slows down the program

C Allows floating point values

D Makes code easier to read by using names instead of numbers

Enums improve code readability by replacing numbers with meaningful names.

Can enum members have duplicate values?

A Yes, but it is not recommended

B No, it causes a compile error

C Only if they are consecutive

D Only if they are the first two members

Enum members can have the same value, but it can cause confusion and is usually avoided.

Explain what an enum is and how it helps in C programming.

Think about how enums replace numbers with names.

Describe how to assign specific values to enum members and what happens to members without assigned values.

Consider how numbering works inside enums.