https://DevOpsCloud.io -- Cloud Monk Losang Jinpa, Ph.D., MCSE/MCT, GitOps DevOps Engineer

Java Double.isNaN() is a static method in the Java Double class that checks whether a Java double value is “Not-a-Number” (NaN). It is used to handle and detect undefined or erroneous results in floating-point calculations. Introduced in Java 2004 with Java 5, isNaN() is critical in scientific and financial applications where NaN values may occur due to invalid operations like division by zero.

https://docs.oracle.com/javase/8/docs/api/java/lang/Double.html