Java Interview Guide : 200+ Interview Questions and Answers - Asserts and Garbage Collection

The video tutorial covers two main topics: assertions and garbage collection in Java. It begins by explaining assertions, introduced in Java 1.4, as a way to check for conditions that should never occur in a program. Assertions are not meant for input validation; instead, exceptions like IllegalArgumentException should be used. The tutorial then shifts to garbage collection, describing how Java automatically manages memory by removing objects without references. It explains when garbage collection occurs, such as when memory is low or the CPU is idle, and advises against using System.gc() in code.

What is the primary purpose of assertions in Java?

• To check for conditions that should never occur

• To validate user input

• To optimize code performance

• To handle exceptions

When should you use an IllegalArgumentException instead of an assertion?

• When checking for conditions that should never occur

• When validating input data

• When optimizing code performance

• When handling runtime exceptions

How does Java handle memory management compared to languages like C and C++?

• Java requires manual memory management

• Java uses pointers for memory management

• Java does not manage memory

• Java uses automatic garbage collection

What happens to an object in Java when it no longer has any references?

• It causes a memory leak

• It is immediately deleted

• It becomes eligible for garbage collection

• It is moved to a temporary storage

What triggers the Java garbage collector to run?

• When a new object is created

• At a fixed time interval

• When the heap is full or CPU is idle

• When the program starts

What is the role of the System.gc() method in Java?

• It forces garbage collection to run immediately

• It is a request for garbage collection, not a command

• It deallocates all unused objects

• It optimizes memory usage

Why is it generally not recommended to use System.gc() in Java programs?

• It can cause program crashes

• It is just a request and may not be honored

• It is not effective in freeing memory

• It can lead to memory leaks