Where is the default hashCode method value defined in Java?

In Java, the hashCode() method is defined by default in the java.lang.Object class. Its implementation returns an integer value, which is usually related to the internal address of the object in memory, but the specification does not guarantee a specific algorithm.

This value is used for quick comparisons of objects in hash-based structures such as HashMap or HashSet. When overriding the equals() method, it is recommended to also override hashCode() to maintain the contract between them.

Example of calling the default hashCode:

Object obj = new Object();
int hash = obj.hashCode();
System.out.println(hash);