Mastering Java Concepts

What is the main purpose of the Java Virtual Machine (JVM)?

• To manage memory allocation and garbage collection.

• To provide a graphical user interface for Java applications.

• To compile Java source code into machine code.

• To execute Java bytecode and provide platform independence.

Explain the difference between JDK, JRE, and JVM.

• JDK is for development, JRE is for running applications, and JVM is the execution engine.

• JDK is for running applications, JRE is for development, and JVM is a framework.

• JDK is a type of application, JRE is a library, and JVM is a compiler.

• JDK is the runtime environment, JRE is for development, and JVM is a programming language.

What are the four main principles of Object-Oriented Programming in Java?

• Encapsulation, Inheritance, Polymorphism, Abstraction

• Composition, Aggregation, Serialization, Reflection

• Inheritance, Overloading, Exception Handling, Modularity

• Encapsulation, Data Hiding, Static Binding, Dynamic Dispatch

How does Java achieve platform independence?

• Java uses native code for each platform.

• Java relies on operating system compatibility.

• Java uses bytecode and the Java Virtual Machine (JVM) to achieve platform independence.

• Java compiles directly to machine code.

What is the significance of the 'main' method in a Java program?

• The 'main' method is where all variables are declared.

• The 'main' method is used for defining classes in Java.

• The 'main' method is responsible for garbage collection in Java.

• The 'main' method is the entry point for Java applications.