Do you use the equals method for comparing objects when adding them to a bucket-based data structure?

Yes, when working with data structures that use buckets (such as HashMap, HashSet), the equals method plays a key role in correctly comparing objects.

The principle of such structures:

• First, the hash code of the object is computed using the hashCode() method to determine the bucket.
• Then, if there are multiple objects in the bucket (collision), the equals() method is called for precise comparison of objects to determine if they are the same.

Therefore, for correct operation with such structures, it is important to override both methods — hashCode() and equals() — in accordance with the object comparison logic.

Example:

public class Person {
    private String id;
    private String name;

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Person person = (Person) o;
        return id.equals(person.id);
    }

    @Override
    public int hashCode() {
        return id.hashCode();
    }
}

Without a correct equals, objects may be compared incorrectly, leading to errors when adding or searching in collections with buckets.