Where in practice and under what tasks is the verification of the equivalence of objects used?

Question

Java

In what tasks is it necessary to check the equivalence of equals objects? When it may be needed, preferably on some example.

Answer 1

In most cases, the equals + hashCode method is implemented so that the class object is correctly stored in the Map and Set collections. The internal implementation of collections uses these methods.

Answer 2

String comparison for example