[LANG-381] NumberUtils.min(floatArray) returns wrong value if floatArray[0] happens to be Float.NaN

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.3
• Fix Version/s: 2.4
• Assignee: Unassigned
• Reporter: Thomas Vandahl
• Created: 30/Nov/07 13:17
• Updated: 06/Jan/08 23:59
• Resolved: 06/Jan/08 23:59

Description

The min() method of NumberUtils returns the wrong result if the first value of the array happens to be Float.NaN. The following code snippet shows the behaviour:

float a[] = new float[]

{(float) 1.2, Float.NaN, (float) 3.7, (float) 27.0, (float) 42.0, Float.NaN}

;
float b[] = new float[]

{Float.NaN, (float) 1.2, Float.NaN, (float) 3.7, (float) 27.0, (float) 42.0, Float.NaN}

;

float min = NumberUtils.min(a);
System.out.println("min(a): " + min); // output: 1.2
min = NumberUtils.min(b);
System.out.println("min(b): " + min); // output: NaN

This problem may exist for double-arrays as well.

Proposal: Use Float.compare(float, float) or NumberUtils.compare(float, float) to achieve a consistent result.