Why is BigDecimal natural ordering inconsistent with equals?

Question

From the Javadoc for BigDecimal:

Note: care should be exercised if BigDecimal objects are used as keys in a SortedMap or ele

Answer 1

The answer is pretty short. equals() method compares objects while compareTo() compares values. In case of BigDecimal different objects can represent same value. Thats why equals() might return false, while compareTo() returns 0.

equal objects => equal values

equal values =/> equal objects

Object is just a computer representation of a some real world value. For example same picture might be represented in a GIF and JPEG formats. Thats very like BigDecimal, where same value might have distinct representations.