How is the hashCode() method implemented for an object of type Any in Kotlin, and what role does it play?

In Kotlin, the hashCode() method for an object of type Any is implemented to return an integer value that serves as the hash of the object. By default, it is usually based on the internal memory address of the object, which ensures uniqueness for different instances.

The role of hashCode() is to be used in hash-based collections (such as HashMap, HashSet) for quick search and comparison of objects. It is important that if two objects are equal (equals returns true), then their hashCode should be the same.

Example of overriding hashCode in Kotlin:

data class User(val id: Int, val name: String)

// data class automatically generates hashCode and equals

If hashCode is not overridden, the implementation from Any will be used, which may not be suitable for content-based object comparison logic.