rspec/rules/S2185/java/rule.adoc

Certain math operations are just silly and should not be performed because their results are predictable.


In particular, ``++anyValue % 1++`` is silly because it will always return 0.


Casting a non-floating-point value to floating-point and then passing it to ``++Math.round++``, ``++Math.ceil++``, or ``++Math.floor++`` is silly  because the result will always be the original value. 


These operations are silly with any constant value: ``++Math.abs++``, ``++Math.ceil++``, ``++Math.floor++``, ``++Math.rint++``, ``++Math.round++``.


And these oprations are silly with certain constant values:


||Operation||Value||

|acos|0.0 or 1.0|

|asin|0.0 or 1.0|

|atan|0.0 or 1.0|

|atan2|0.0|

|cbrt|0.0 or 1.0|

|cos|0.0|

|cosh|0.0|

|exp|0.0 or 1.0|

|expm1|0.0|

|log|0.0 or 1.0|

|log10|0.0 or 1.0|

|sin|0.0|

|sinh|0.0|

|sqrt|0.0 or 1.0|

|tan|0.0|

|tanh|0.0|

|toDegrees|0.0 or 1.0|

|toRadians|0.0|


== Noncompliant Code Example

----
public void doMath(int a) {
  double floor = Math.floor((double)a); // Noncompliant
  double ceiling = Math.ceil(4.2);  // Noncompliant
  double arcTan = Math.atan(0.0);  // Noncompliant
}
----