JUnit assertEquals (double expected, double actual, double epsilon)

Question

Possible duplicate:
JUnit: assertEquals for double values

assertEquals(double expected, double actual) seems to be deprecated.

Javadocs for JUnit are surprisingly not enough, and its widespread use. Can you show me how to use the new assertEquals(double expected, double actual, double epsilon) ?

Answer 1

Epsilon is your “phase factor,” since paired discharges may not be exactly the same. Epsilon lets you describe how close they are.

If you expected 3.14159, but would take anywhere from 3.14059 to 3.14259 (i.e. within 0.001), then you should write something like

 double myPi = 22.0d / 7.0d; //Don't use this in real life! assertEquals(3.14159, myPi, 0.001); 

(By the way, 22/7 comes out in 3.1428+, and this statement will not be fulfilled. This is good.)