Question

I need a final review and some tips about a function I wrote.

  public static Integer max(Integer... pNumber) {
    Integer lResult = null;
    for (Integer lNumber : pNumber) {
      if (lResult == null || (null != lNumber && lNumber > lResult)) {
        lResult = lNumber;
      }
    }
    return lResult;
  }

I am not realy sure if my code is elegant.
null parameters as well as a null result is possible.
However… I have the feeling that I solved something in the code to complicated.
The function is part of an utility class which is used by the company.
using third party librarys is not allowed.

Here the corresponding test:

@Test
public void testMaxWithInteger() {
  assertEquals(new Integer(9), NumberUtils.max(4, 2, -4, null, 9, 5));    
}

Thanks in advance

Answer 1

IMHO I wouldn’t use null objects as Integer[] can use 6x as much memory as using int[]

public static Integer max(Integer... ints) {
    long ret = Long.MIN_VALUE;
    for (Integer i: ints) 
      if (null != i && i > ret) 
        ret = i;
    return ret >= Integer.MIN_VALUE? (int) ret : null;
}

Instead of Integer[] I would use int[] and leave 0 or Integer.MIN_VALUE as my “un-initialised” value.