c# Enumerations
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The document discusses C# enumerations. It defines an enumeration as a value type that declares a list of named integer constants. An enumeration can be defined inside a class or structure using the enum keyword. Enumerations make code more readable by giving related constants meaningful names and improve maintainability. The document provides an example of a WeekDays enumeration and demonstrates how to access enumeration members and values. It also summarizes common enumeration methods like GetName, GetNames, and GetValues.
![NOW TRY THEM OUT!
public static void Main(string[] args)
{
Console.WriteLine(Enum.GetName(typeof(WeekDays), 4));
Console.WriteLine("weekdays constant names:");
foreach (string str in Enum.GetNames(typeof(WeekDays)))
Console.WriteLine(str);
}
enum WeekDays
{
Monday,
Tuesday,
Wednesday,
Thursday,
Friday,
Saturday,
Sunday
}
// put this within you Main Method
Console.WriteLine(WeekDays.Friday);
Console.WriteLine((int) WeekDays.Friday);](https://image.slidesharecdn.com/enumerations-converted-190903213348/85/c-Enumerations-10-320.jpg)
c# Enumerations
- 1. C# ENUMERATIONS ENGR. MICHEAL OGUNDERO You can contact me via PHONE - +2348087365099 SKYPE – OGUNDERO MICHEAL Email – ogunderoayodeji@gmail.com
- 2. A QUICK ONE! • Write a program that reads an input (integer), day from a user and prints to the console based on the if conditional statements below: If day is 1, print “Monday” If day is 2, print “Tuesday” . . . If day is 7, print “Sunday”
- 3. DEFINITION • An enum is a value type data type used to declare a list of named integer constants. • It can be defined using the enum keyword directly inside a namespace, class, or structure. • The enum is used to give a name to each constant so that the constant integer can be read using its name. • The enum can include named constants of numeric data type e.g. Byte, sbyte, short, ushort, int, uint, long, or ulong.
- 4. EXAMPLE enum WeekDays { Monday = 0, Tuesday =1, Wednesday = 2, Thursday = 3, Friday = 4, Saturday =5, Sunday = 6 } Console.WriteLine(WeekDays.Fri day); Console.WriteLine((int) WeekDays.Friday); • type the code fragment within your Main method • What do you have on your console window?
- 5. ENUMERATIONS… Note this: • By default, the first member of an enum has the value 0 and the value of each successive enum member is increased by 1. • For example, in the following enumeration, Monday is 0, Tuesday is 1, Wednesday is 2. • Edit the code from the previous slide to what we have here enum WeekDays { Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday } // put this within you Main Method Console.WriteLine(WeekDays.Friday); Console.WriteLine((int) WeekDays.Friday);
- 6. ENUMERATIONS… • Try that and see what happens!!! enum WeekDays { Monday=14, Tuesday, Wednesday, Thursday=16, Friday, Saturday, Sunday, } // put this within you Main Method Console.WriteLine(WeekDays.Friday); Console.WriteLine((int) WeekDays.Friday);
- 7. ENUMERATIONS… Note this: • A change in the value of the first enum member will automatically assign incremental values to the other members sequentially. • For example, changing the value of Monday to 14, will assign 15 to Tuesday, 16 to Wednesday, and so on: • Edit the code from the previous slide to what we have here. enum WeekDays { Monday=14, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday } Console.WriteLine(WeekDays.Friday); Console.WriteLine((int) WeekDays.Friday);
- 8. Why DO YOU REALLY NEED ENUMS? • Enum is mainly used to make code more readable by giving related constants a meaningful name. • It also improves maintainability.
- 9. ENUM METHODS • Enum is an abstract class that includes static helper methods to work with enums. Enum method Description Format Converts the specified value of enum type to the specified string format. GetName Returns the name of the constant of the specified value of specified enum. GetNames Returns an array of string name of all the constant of specified enum. GetValues Returns an array of the values of all the constants of specified enum. object Parse(type, string) Converts the string representation of the name or numeric value of one or more enumerated constants to an equivalent enumerated object.
- 10. NOW TRY THEM OUT! public static void Main(string[] args) { Console.WriteLine(Enum.GetName(typeof(WeekDays), 4)); Console.WriteLine("weekdays constant names:"); foreach (string str in Enum.GetNames(typeof(WeekDays))) Console.WriteLine(str); } enum WeekDays { Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday } // put this within you Main Method Console.WriteLine(WeekDays.Friday); Console.WriteLine((int) WeekDays.Friday);