I have a function which return a type int. However, I only have a value of the TAX enumeration.
How can I cast the TAX enumeration value to an int?
public enum TAX {
NOTAX(0),SALESTAX(10),IMPORTEDTAX(5);
private int value;
private TAX(int value){
this.value = value;
}
}
TAX var = TAX.NOTAX; // This value will differ
public int getTaxValue()
{
// what do do here?
// return (int)var;
}
You'd need to make the enum expose value somehow, e.g.
public enum Tax {
NONE(0), SALES(10), IMPORT(5);
private final int value;
private Tax(int value) {
this.value = value;
}
public int getValue() {
return value;
}
}
...
public int getTaxValue() {
Tax tax = Tax.NONE; // Or whatever
return tax.getValue();
}
(I've changed the names to be a bit more conventional and readable, btw.)
This is assuming you want the value assigned in the constructor. If that's not what you want, you'll need to give us more information.
myEnumValue = MyEnum.valueOf(myInt); the arg has to be of type String - or is there something I am missing?
I prefer this:
public enum Color {
White,
Green,
Blue,
Purple,
Orange,
Red
}
then:
//cast enum to int
int color = Color.Blue.ordinal();
Sometime some C# approach makes the life easier in Java world..:
class XLINK {
static final short PAYLOAD = 102, ACK = 103, PAYLOAD_AND_ACK = 104;
}
//Now is trivial to use it like a C# enum:
int rcv = XLINK.ACK;
If you want the value you are assigning in the constructor, you need to add a method in the enum definition to return that value.
If you want a unique number that represent the enum value, you can use ordinal().
ordinal() than valid use cases for ordinal(). If you need to store a unique value for the enum, then just store the enum. There are EnumSets, Lists of Enums, EnumMaps, and nearly any other Enum collection you might want available.
ordinal() because the OP didn't make it clear what he wanted the int to actually be.
ordinal() internally within the enum itself. For example, say I have an enum called "Season" which contains the values Spring, Summer, Autumn, and Winter, and it has a public method called next() which returns values()[(ordinal() + 1) % 4] Externally, no code ever sees the ordinal number, and there will never be additional members in this enum, so it seems like a valid use-case.
ordinal() hinge on far flung code being broken by changes to the enum enumeration constants. If you're going to modify the enum's constants you'd have to be in that file already. Most enums are fairly short, and if it's not you should be checking the file more thoroughly anyway. In both cases you should probably have a unit test covering your next() method anyway.Maybe it's better to use a String representation than an integer, because the String is still valid if values are added to the enum. You can use the enum's name() method to convert the enum value to a String an the enum's valueOf() method to create an enum representation from the String again. The following example shows how to convert the enum value to String and back (ValueType is an enum):
ValueType expected = ValueType.FLOAT;
String value = expected.name();
System.out.println("Name value: " + value);
ValueType actual = ValueType.valueOf(value);
if(expected.equals(actual)) System.out.println("Values are equal");
public enum ProfileType {
PRIVATE,
PUBLIC
}
private ProfileType profileType = ProfileType.PRIVATE;
If you want to get int from profileType you can simply do:
int profileTypeInt = profileType.ordinal();
public enum Tax {
NONE(1), SALES(2), IMPORT(3);
private final int value;
private Tax(int value) {
this.value = value;
}
public String toString() {
return Integer.toString(value);
}
}
class Test {
System.out.println(Tax.NONE); //Just an example.
}
A somewhat different approach (at least on Android) is to use the IntDef annotation to combine a set of int constants
@IntDef({NOTAX, SALESTAX, IMPORTEDTAX})
@interface TAX {}
int NOTAX = 0;
int SALESTAX = 10;
int IMPORTEDTAX = 5;
Use as function parameter:
void computeTax(@TAX int taxPercentage){...}
or in a variable declaration:
@TAX int currentTax = IMPORTEDTAX;
