LESSON 46 / 75·2 min readIntermediate

Important interview questions for Java

Good to knowConcept lesson
01 Understand02 Recall03 Prepare
  1. Explain difference between ArrayList and LinkedList.
  2. When do you use HashMap vs TreeMap?
  3. How does PriorityQueue work?
  4. What is the difference between == and .equals() in Java?
  5. Why is String immutable?
  6. How do you detect a cycle in a linked list?
  7. What is the difference between BFS and DFS?
  8. Why is binary search efficient?
  9. How do you handle recursion limit problems?
  10. Explain time complexity of hashmap operations.

PAUSE & RECALL

Can you explain it without the notes?

Important interview questions for Java

Use your own words. Explain an example and one limitation before checking the explanation.

Check your explanation
  1. Explain difference between ArrayList and LinkedList.
CONNECT IT TO YOUR INTERVIEW

Turn this concept into a clear answer.

Practice this concept
YOUR NEXT STEP

Keep connecting the ideas.

Next lesson: Best Java DSA interview practice list

Adapted from 15_DSA_JAVA.md · “13. Important interview questions for Java”. Examples are study fragments; framework behavior can depend on your version.