Core JAVA Unit 1

Questions and Answers

What is the primary purpose of Java?

To write once and run anywhere (WORA)

Who developed Java?

James Gosling

Which of these statements about Java is true?

Java is a low-level programming language.

Java is platform-independent. (correct)

Java requires recompilation to run on different platforms.

Java was released in 2000.

Java applications are compiled to bytecode.

True Signup and view all the answers

What does JVM stand for?

Java Virtual Machine Signup and view all the answers

Java code is compiled to __________.

bytecode Signup and view all the answers

What is included in the Java Development Kit (JDK)?

All of the above Signup and view all the answers

What is the role of the Garbage Collector in Java?

To manage memory by deleting unreferenced objects Signup and view all the answers

You can compile a Java program without JDK installed.

False Signup and view all the answers

Match the following parts of Java with their definitions:

JDK = Java Development Kit that includes everything for Java development JRE = Java Runtime Environment that allows Java programs to run JVM = Java Virtual Machine that executes bytecode Garbage Collector = Handles memory management by deleting unreferenced objects Signup and view all the answers

Study Notes

Introduction to Java

Java is a class-based, object-oriented programming language focused on minimal implementation dependencies.
It supports the concept of "Write Once, Run Anywhere" (WORA), allowing compiled Java code to run on any platform that supports Java without recompilation.
Released in 1995 and developed by James Gosling at Sun Microsystems, which is now part of Oracle Corporation.
Noted for its simplicity, robustness, and security, making it popular for enterprise-level applications.
Java applications generate bytecode, which is executed by the Java Virtual Machine (JVM).

Java Terminology

Java Virtual Machine (JVM): Executes bytecode generated by the Java compiler (JAVAC) and ensures platform independence.
Bytecode: The compiled form of Java source code, saved as a .class file, ready for execution by the JVM.
Java Development Kit (JDK): A comprehensive toolkit including the compiler, Java Runtime Environment (JRE), debuggers, and more, necessary for creating and running Java programs.
Java Runtime Environment (JRE): Component of JDK required to run Java applications, includes JVM and support browser, applet, and plugins but not compilation.
Garbage Collector: Automatic memory management tool in Java that reclaims memory from unreferenced objects, simplifying memory management for programmers.
ClassPath: The file path where the Java runtime and compiler look for .class files, defaults include JDK libraries; external libraries must be added to this path.

Features of Java

Platform Independent: Java’s bytecode can execute on any operating system (Windows, Linux, macOS) without modification due to the unique JVM for each OS.
Object-Oriented Programming Language: Utilizes objects and classes, based on four main concepts:
- Abstraction: Hiding complex realities while exposing only the necessary parts.
- Encapsulation: Bundling data with methods that operate on that data.
- Inheritance: Mechanism for a new class to inherit properties and behavior from an existing class.
- Polymorphism: Ability to present the same interface for different underlying data types.
Simplicity: Lacks complex features such as pointers, operator overloading, and multiple inheritance, making it easier to learn and use.
Robustness: Designed to detect and handle errors early, with extensive error-checking capabilities, improving reliability.

Description

Explore the fundamentals of Java in this quiz based on Unit 1 of the Core JAVA curriculum. Learn about Java's object-oriented principles and its significance in application development. Test your knowledge on the key concepts that make Java a versatile programming language.