Java Core Class (Type, File)

15. StringBuffer, StringBuilder, String

1. What is String in java.

2. Ways to create a string.

3. Benefits of strings are immutable?

4. String constant pool.

5. StringBuilder important details.

6. StringBuilder vs String.

7. StringBuffer important details.

8. StringBuilder vs StringBuffer.

9. Best practice to choose between String, StringBuilder and StringBuffer.

16. Equals/hashCode contract

1. Default behavior of equals and hashCode methods.

2. HashCode method overriding rules.

3. Equals method overriding rules.

4. A contract between Equals and hashCode methods.

5. Why methods connected to each other? Describe result of scenarios when one of them is overridden but the other not: side effects.

6. Difference between ‘==’ and equals.

7. Collections and equals/hashCode dependencies, best practice.