How to get Enum Value from index in Java?
Try this
Months.values()[index]
Here's three ways to do it.
public enum Months {
JAN(1), FEB(2), MAR(3), APR(4), MAY(5), JUN(6), JUL(7), AUG(8), SEP(9), OCT(10), NOV(11), DEC(12);
int monthOrdinal = 0;
Months(int ord) {
this.monthOrdinal = ord;
}
public static Months byOrdinal2ndWay(int ord) {
return Months.values()[ord-1]; // less safe
}
public static Months byOrdinal(int ord) {
for (Months m : Months.values()) {
if (m.monthOrdinal == ord) {
return m;
}
}
return null;
}
public static Months[] MONTHS_INDEXED = new Months[] { null, JAN, FEB, MAR, APR, MAY, JUN, JUL, AUG, SEP, OCT, NOV, DEC };
}
import static junit.framework.Assert.assertEquals;
import org.junit.Test;
public class MonthsTest {
@Test
public void test_indexed_access() {
assertEquals(Months.MONTHS_INDEXED[1], Months.JAN);
assertEquals(Months.MONTHS_INDEXED[2], Months.FEB);
assertEquals(Months.byOrdinal(1), Months.JAN);
assertEquals(Months.byOrdinal(2), Months.FEB);
assertEquals(Months.byOrdinal2ndWay(1), Months.JAN);
assertEquals(Months.byOrdinal2ndWay(2), Months.FEB);
}
}
I just tried the same and came up with following solution:
public enum Countries {
TEXAS,
FLORIDA,
OKLAHOMA,
KENTUCKY;
private static Countries[] list = Countries.values();
public static Countries getCountry(int i) {
return list[i];
}
public static int listGetLastIndex() {
return list.length - 1;
}
}
The class has it's own values saved inside an array, and I use the array to get the enum at indexposition. As mentioned above arrays begin to count from 0, if you want your index to start from '1' simply change these two methods to:
public static String getCountry(int i) {
return list[(i - 1)];
}
public static int listGetLastIndex() {
return list.length;
}
Inside my Main I get the needed countries-object with
public static void main(String[] args) {
int i = Countries.listGetLastIndex();
Countries currCountry = Countries.getCountry(i);
}
which sets currCountry to the last country, in this case Countries.KENTUCKY.
Just remember this code is very affected by ArrayOutOfBoundsExceptions if you're using hardcoded indicies to get your objects.