What is the Java Virtual Machine (JVM)?

The JVM is a runtime environment that executes Java bytecode and provides platform independence, memory management, and garbage collection for Java applications.

What is the difference between JDK and JRE?

The JDK includes tools for developing Java applications, while the JRE provides the runtime environment required to execute Java programs.

What are Java collections?

Java collections are data structures from the java.util package, such as List, Set, and Map, that provide methods for storing, accessing, and manipulating groups of objects.

Java Interview Questions

121. How does generational garbage collection work?

122. What are stop-the-world pauses?

123. How do concurrent garbage collectors reduce pause times?

124. How would you tune JVM garbage collection for large applications?

125. What metrics indicate unhealthy garbage collection behavior?

126. How would you debug out-of-memory errors in Java?

127. What are heap dumps and how are they analyzed?

128. How do thread dumps help diagnose JVM issues?

129. What are common causes of high CPU usage in Java applications?

130. How would you profile Java applications in production?