Java Inheritance and Polymorphism: Concepts and Examples
Java Inheritance and Polymorphism
Multilevel Inheritance
Multilevel inheritance in Java occurs when a class is derived from a class that is also derived from another class, creating a chain of inheritance.
Example:
class Animal {
public void eat() {
System.out.println("Animal is eating");
}
}
class Dog extends Animal {
public void bark() {
System.out.println("Dog is barking");
}
}
class GoldenRetriever extends Dog {
public void fetch() {
System.out.println(Essential Concepts in Computer Hardware and Software
Computer Hardware and Software Fundamentals
1. Computer Hardware
Computer hardware is the collection of physical elements that constitutes a computer system. Computer hardware refers to the physical parts or components of a computer such as the monitor, mouse, keyboard, etc., all of which are physical objects that can be touched. In contrast, software is instructions that can be stored and run by hardware. That is any set of machine-readable instructions that directs a computer’s processor to perform
Read MoreUnderstanding the OSI Model and Network Communication
Item 4: The Importance of Networking
First Isolated Equipment
Initially, isolated equipment led to several challenges:
- Duplication of devices, equipment, and resources.
- Inability to communicate effectively.
- Lack of control and network management.
The Need for Standards
In the 1970s, there was no unification of protocols. For a company to expand its network, it could only go to the original manufacturer. This created conflicts between business network systems from different manufacturers.
The OSI Reference
Read MoreComputer Science Fundamentals: From Assembly to Operating Systems
Second-Generation: Assembly Language
- A mnemonic system for representing machine instructions:
- Mnemonic names for op-codes
- Identifiers: Descriptive names for memory locations, chosen by the programmer
Assembly Language Characteristics
- One-to-one correspondence between machine instructions and assembly instructions:
- The programmer must think like the machine
- Inherently machine-dependent
- Converted to machine language by a program called an assembler
Third-Generation Languages
- Uses high-level primitives:
- Similar
Understanding Computers: Types, Elements, and Languages
What is a Mainframe Computer?
A mainframe computer is a high-capacity system designed for intensive computational tasks. Mainframes typically have multiple users connected through terminals. The most powerful mainframes, called supercomputers, perform very complex and time-consuming calculations.
What is a Microcomputer?
A microcomputer is a device, such as a laptop, that uses a microprocessor as its central processing unit (CPU). Common microcomputers include PCs, home computers, and computers for
Read MoreProcess and Memory Management in Operating Systems
Resource Management
Processes and Flows
- Def Process: Program in execution.
- Homepage More names:
- Control-Flow
- Tasks
- Threads (I will comment with a Java language example)
- Thread (of execution)
- The Operating System (OS) assigns a data structure (BCP) to all processes.
- What does the BCP contain?
- Current status
- Process Identifier
- Process priority
- Location in memory
- Resources used
Thread and States of Processes
- Def Thread: Point of execution of a process (a process can have one or more threads).
- Example: Word running