Intermediate·Concept·2 min read

Important interview questions for Java

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  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.

Adapted from 15_DSA_JAVA.md · “13. Important interview questions for Java”. Code examples are study fragments. Difficulty and core labels are editorial estimates; version-specific behavior should be checked against your project.