What is the role of the hashCode method in working with objects in Java?

The hashCode method in Java is used to obtain an integer value (hash code) of an object, which is used for quick search and comparison of objects in data structures such as HashMap, HashSet, and Hashtable.

Main points:

• If two objects are equal according to the equals() method, their hashCode() should return the same value.
• If hashCode() returns different values for two objects, they are considered different when used in hash structures.
• When overriding equals(), you should also override hashCode() to maintain the contract between them.

Example of overriding:

@Override
public int hashCode() {
    return Objects.hash(field1, field2);
}