Operations on arrays, primitive arrays (like int[]
) and
* primitive wrapper arrays (like Integer[]
).
This class tries to handle null
input gracefully.
* An exception will not be thrown for a null
* array input. However, an Object array that contains a null
* element may throw an exception. Each method documents its behaviour.
Finds the index of the given object in the array.
* *This method returns {@link #INDEX_NOT_FOUND} (-1
) for a null
input array.
null
* @param objectToFind the object to find, may be null
* @return the index of the object within the array,
* {@link #INDEX_NOT_FOUND} (-1
) if not found or null
array input
*/
public static int indexOf(Object[] array, Object objectToFind) {
return indexOf(array, objectToFind, 0);
}
/**
* Finds the index of the given object in the array starting at the given index.
* *This method returns {@link #INDEX_NOT_FOUND} (-1
) for a null
input array.
A negative startIndex is treated as zero. A startIndex larger than the array
* length will return {@link #INDEX_NOT_FOUND} (-1
).
null
* @param objectToFind the object to find, may be null
* @param startIndex the index to start searching at
* @return the index of the object within the array starting at the index,
* {@link #INDEX_NOT_FOUND} (-1
) if not found or null
array input
*/
public static int indexOf(Object[] array, Object objectToFind, int startIndex) {
if (array == null) {
return -1;
}
if (startIndex < 0) {
startIndex = 0;
}
if (objectToFind == null) {
for (int i = startIndex; i < array.length; i++) {
if (array[i] == null) {
return i;
}
}
} else {
for (int i = startIndex; i < array.length; i++) {
if (objectToFind.equals(array[i])) {
return i;
}
}
}
return -1;
}
}