Where is Java's Array indexOf?
There are a couple of ways to accomplish this using the Arrays
utility class.
If the array is not sorted and is not an array of primitives:
java.util.Arrays.asList(theArray).indexOf(o)
If the array is primitives and not sorted, one should use a solution offered by one of the other answers such as Kerem Baydoğan's, Andrew McKinlay's or Mishax's. The above code will compile even if theArray
is primitive (possibly emitting a warning) but you'll get totally incorrect results nonetheless.
If the array is sorted, you can make use of a binary search for performance:
java.util.Arrays.binarySearch(theArray, o)
Array has no indexOf()
method.
Maybe this Apache Commons Lang ArrayUtils
method is what you are looking for
import org.apache.commons.lang3.ArrayUtils;
String[] colours = { "Red", "Orange", "Yellow", "Green" };
int indexOfYellow = ArrayUtils.indexOf(colours, "Yellow");
For primitives, if you want to avoid boxing, Guava has helpers for primitive arrays e.g. Ints.indexOf(int[] array, int target)