Java Tutorial # 26 | Enumerations in Java | Enums in Java | Java Beginners Tutorials by Java9s

Enums in Java help to define constants which are more powerful than we do with Interfaces. The main objective of Enums is to ensure the type safety when using the Constants in Java programs. In this Video tutorial i have explained how enums work and how objects can be created. I have also explained about some the important methods of enum like values() valueOf(String), Ordinal(), name() etc. All the object produced by enum are singleton. And enum provided a great flexibility to add more values to constant and define methods like a normal class.

[jvsnyc]

I found the first example easier to absorb immediately than the second was, possibly because the second were about ranges, or just slightly less time was spent on it. Anyway, subscribed and I am going to be keeping you in mind when seeking Java information. One thing none of the tutorials I've watched showed was when we needed to have specific integral values for enums that corresponded to some external hardware or software system, something like
enum Commands { SEND = 10, RECEIVE = 20, CLEAR = 32, SIGNAL_BUFFER_FULL = 60 }
At least in the old days, that was a very common use of enums, to let our program deal with externally-imposed magic numbers. None of the tutorials I've seen really showed how to do that, including this one. I guess we could use a constructor and a private value to do that, something like
enum Commands { SEND(10), RECEIVE(20), CLEAR(32), SIGNAL_BUFFER_FULL(60);
private int chipCommand;
private Commands( int cCMD )
{
chipCommand = cCMD;
}
public int getCmdValue()
{
return chipCommand;
}
Then when we need the values we do something like Commands.SEND.getCmdValue();
Obviously, the people who made the enums in Java 5 had been using enums in C/C++ and other languages for years, and had been thinking about what they liked and disliked about them and how they could make them better. C# enums are beautifully simple and clean, but now I see how there is also a lot to like about Java's implementation.

[rakeshkonda]

I use enums but never observed these many details before...good one

[arjunsuresh]

One of the best explanation on enums.Thank you!!

[thundrking]

A complete tutorial on enums. Thanks !!

[saikiran]

Very good tutorial. Srini can you please share link for the code for these videos

[subhajitmitra]

thnx a ton, it was completely unknown to me!

[SudiptaDeb]

Very good Video... Love it. Just one small suggestion: Please include how Enum can be used for implementing Singleton Design Pattern. The best uses of Enum...

[sumanreddy]

Presentation is lovely .. I appreciate the pain taken by you for us

how to change the value in the enums  like

CHICKEN_SOUP(20)   to  CHICKEN(30)  by programmatically this is missing in the presentation ..

[krishnasampath]

Thanks a lot, could you provide link to java9s and the source code for enum

[Nareshgvlogs]

why enum is not allowing values which are started with Integers?

[kishansatasiya]

nice u have exposed enum that is not done at class room !!!

[muddassirahmed]

i still don't get a clear idea of enums, and how do their methods work.

[jatinlalwani]

i executed my program without declaring my constructor private...'

enum boy
{ jatin("mast", 20),
amit("haggu", 20),
sagar("charkhat", 20);

private final String desc;
private final int age;

boy(String desc, int age)
{
this.desc=desc;
this.age=age;}

String getdesc()
{ return desc;}

int getage()
{ return age;
}

}

class asd
{ public static void main(String args[])
{
for(boy a: boy.values())
System.out.println("Name is "+a+". He is "+a.getdesc()+". He is "+a.getage()+" years old.");
}}