Sollicitatievraag bij S&P Global

1. ArrayList vs HashMap 2. Multiple threads accessing a HashMap for get operation. 3. abstract class vs interface java when to use 4. Diamond problem 5. Parent and child class have same method but throws different errors 6. How are procedures executed in java 7. Authentication system design Db queries: a. inner join question, b. select dept names who have more than 2 employees ?