Answer to your question is yes, objects of custom classes can be used as a key in a HashMap.
Read moreHow does a HashMap store items in memory?
A HashMap stores data into multiple singly linked lists of entries (also called buckets or bins) . … All the keys with the same hash value are put in the same linked list (bucket). Keys with different hash values can end-up in the same bucket.
Read moreHow does HashMap store data?
HashMap uses multiple buckets and each bucket points to a Singly Linked List where the entries (nodes) are stored . Once the bucket is identified by the hash function using hashcode, then hashCode is used to check if there is already a key with the same hashCode or not in the bucket(singly linked list).
Read moreWhat do you mean by polymorphism in Java?
Polymorphism means “many forms “, and it occurs when we have many classes that are related to each other by inheritance. Like we specified in the previous chapter; Inheritance lets us inherit attributes and methods from another class. Polymorphism uses those methods to perform different tasks.
Read moreWhat is case study on payroll system using polymorphism?
Now we use an abstract method and polymorphism to perform payroll calculations based on the type of employee . We create an enhanced employee hierarchy to solve the following problem: A company pays its employees on a weekly basis.
Read moreWhich Java class programming technique shows the use of polymorphism?
Since both the definition are different in those classes, calc_grade() will work in different way for same input from different objects. Hence it shows polymorphism.
Read moreHow do you ask a name in Java?
Type a first name, and then hit the enter key on your keyboard . After you hit the enter key, java will take whatever was typed and store it in the variable name to the left of the equals sign. For us, this was the variable called first_name.
Read more