array[1] = null;
        assertThat(ArrayUtil.indexOf(array, null), is(1));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testIndexOf_character() throws Exception {
        final char[] array = new char[] { 'a', 'b', 'c' };
        assertThat(ArrayUtil.indexOf(array, 'a'), is(0));
        assertThat(ArrayUtil.indexOf(array, 'd'), is(-1));
    }

    /**