Additional Notes
What happens if you don’t override hashCode() when overriding equals()?
Track: Java
Topic: Core Java
Focus: Code Reading with Collections
Java: Code Reading with Collections
Answer
It can cause inconsistent behavior in collections like HashMap.
If you override equals() but not hashCode(), objects that are 'equal' may have different hash codes, causing them to be placed in different buckets in a HashMap. This breaks the contract, leading to unexpected behavior, such as not finding an object even though it exists. Always override both methods to maintain consistency.
If you override equals() but not hashCode(), objects that are 'equal' may have different hash codes, causing them to be placed in different buckets in a HashMap. This breaks the contract, leading to unexpected behavior, such as not finding an object even though it exists. Always override both methods to maintain consistency.
Topics: Code Reading with Collections Core Java Java