Java Assert Double is NaN [closed]

Question

I am trying to assert that my double is NaN. Here is a code snippet:

private Double calculateIt(String input){...}

assertEquals(Double.NaN, calculateIt("input text"));

The code does not compile, Double.NaN is defined as primitive

public static final double NaN = 0.0d / 0.0;

To make the assertion work I wrap NaN with a Double object.

assertEquals(new Double(Double.NaN), calculateIt("input text"));

Is there a shorter way to do this?

Answer 1

You could use:

boolean isNan = Double.isNaN(calculateIt("input text"));
assertTrue(isNan);

Double.NaN values cannot be compared with == (Double.NaN == Double.NaN will return false), because NaN is considered as a special one.

More info:

• IEEE floating point