Use the enumerated ordinal () method with caution ~

Copyright Disclaimer: I have been touched by a section on enumeration in the Java impact tive book ~ Not original ~

Let's start with an enumeration:

 
Public Enum enumarmylvltype {defaults 0, en_armu_lvl_type_divine,/* 1. x/en_armu_lvl_type_outstanding,/* 2. excellent */en_armu_lvl_type_elite,/* 3. elite */Category 4, Category 5, en_armu_lvl_type_normal,/* 6. normal */;
 

 

 

This is a simple enumeration type that represents the monster's quality level.

 

Sometimes, we need to pass data out. For example, if the android client sends data to the C ++ server, it is impossible for us to directly transfer the enumerated variables ?~ This is so cute ~

 

As a result, I am smart and will normally do this:

Int iarmylvltype = enumarmylvltype. en_armu_lvl_type_outstanding.ordinal ();

This is correct. It's good ~ However, this is not safe ~

Why? This is because the ordinal method is not specifically used for the corresponding relationship. It is only a sequence number of the enumerated variable.

The truth is simple, just like...

In short, this is not professional ~ Even so, it cannot be said to be wrong.

It's like... You know, I'm no better

We cannot be clever ~ What the ordinal () method gets is a sequence number, which is just a sequence number. We are not allowed to use it for correspondence ~

Hey, don't yell at me ~ Look at the following practice. Are you feeling a lot better ?~

This uses the constructor of the enumeration class to specify the value corresponding to the enumeration variable ~

 
Public Enum enumarmylvltype {/* Find anything different here? No "cmd," these variables are full. If (1) is added, the constructor */en_armu_lvl_type_divine (1),/* 1. god will */en_armu_lvl_type_outstanding (2),/* 2. excellent */en_armu_lvl_type_elite (3),/* 3. elite */en_armu_lvl_type_normal (6),/* 6. normal */; private int inum = 0;/* constructor. Remember that it must be private ~ */Private enumarmylvltype (INT inum) {This. inum = inum;}/* replace the ordinal () method with this method, which is safe, professional, and optional ~ */Public int tonumber () {return this. inum ;}}
 

 

 

How is it? See it? In this way, we can convert it like this:

 
Int iarmylvltype = enumarmylvltype. en_armu_lvl_type_outstanding.tonumer ();
 

In this way, the tonumber () function is specifically used for the corresponding relationship. This function is dedicated, professional, and has no side effects. Please try it ~

For knowledge about enumeration constructors, go to Baidu ~ You are not allowed to ask me ~

PS:

Some may say, why is it so troublesome? Why does en_armu_lvl_type_normal (6),/* 6. Common */correspond to 6 numbers? Simply change to 4, there is no trouble at all, so that you can easily use the ordinal method ~!

This is not the case if you listen to my explanation. You listen to my explanation... wife, please listen to my explanation. This is just a misunderstanding...

Sorry, it's so amazing.

 

In fact, this is the reason. This is for expansion and convenience of servers.

I don't know the specific reason. In short, the serverProgramThe clerk told me to reserve some space for convenient management.