Equals and hashcode methods

What is the equals and hashCode methods in Java?

• Compares content and generates ID.
• Compares references and generates ID.
• Generates ID and compares references.
• Compares content and references.

What is the difference between the hashCode and equals methods?

• hashCode checks content; equals generates ID.
• equals generates ID; hashCode checks content.
• Both check content.
• Both generate IDs.

Which method is called first, equals or hashCode, in Java?

• equals
• hashCode
• Both called simultaneously
• Depends on object size

What is the hashCode method in Java?

• Generates reference value
• Creates numeric identifier
• Compares object content
• Generates memory address

Why is hashCode used in Java?

• To compare references
• For content-based comparison
• For efficient storage and retrieval
• To generate object IDs

Can we override the equals() and hashCode() methods? How?

• No, only equals.
• Yes, override both.
• Yes, override equals only.
• No, only hashCode.

Is hashCode faster than equals?

• Yes
• No
• Depends on object size
• Depends on JVM version

What happens if we do not override hashCode() and equals() in HashMap?

• HashMap becomes read-only
• Objects become immutable
• Incorrect behavior in HashMap
• Collisions are prevented

Can two objects have the same hashCode?

• No
• Yes
• Only in HashSet
• Only with equal content

What is the connection between equals and hashCode?

• None
• Equal objects have equal hashCode
• equal() calls hashCode()
• hashCode() calls equals()