DCIT 23 midterm

• PDLC


  Program Development Life Cycle - A process that software developers use to create software programs
• Phases of PDLC


  • Conceptualization
  • Design
  • Implementation
  • Testing
  • Deployment
  • Maintenance
• Conceptualization Phase


  Requirements of the software are gathered and analyzed. A project plan is developed.
• Design Phase


  Team will create the software design based on the requirements gathered in the planning stage. Team will also create a prototype or mockup of the software to visualize how it will look and work.
• Implementation Phase


  Team will actually write the code for the software. Team will also perform unit testing.
• Testing Phase


  Team will test the software as a whole, using various techniques to identify and fix any bugs or defects. This includes functional testing.
• Deployment Phase


  Software is released to the end-users. Ongoing maintenance and support may also be provided in this stage.
• Maintenance Phase


  The team will continue to maintain and support the software as needed. May continue for the life of the software, depending on the needs of the users and the organization.
• Java


  Programming language that is used to develop software applications. Can be run on various operating systems without making any modifications. Code written in Java is compiled into bytecode that can be executed on any machine equipped with JVM.
• Java Virtual Machine (JVM)

  Converts the bytecode into machine code that the processor of the computer can execute.
• Java was introduced by Sun Microsystems


  1995
• Java


  • Created by James Gosling, Mike Sheridan & Patrick Naugthon
  • Created to make a program that could run in multiple platforms
  • "Write once, run anywhere"
• Uses of Java in different aspects of technology

  • Web Applications
  • Mobile Applications
  • Enterprise Applications
  • Desktop Applications
  • Gaming
  • Internet of Things (IoT)
  • Machine Learning and Artificial Intelligence
• How Java works

  1. Java Code

  2. Compilation

  3. Loading

  4. Verification

  5. Execution

  6. Garbage Collection

  7. Termination
• Java's programming paradigm


  • Procedural - involves writing a sequence of procedures or functions perform specific tasks
  • Object-Oriented - organizes code into objects that have properties (data) and methods (behavior)
  • Inheritance
  • Encapsulation
  • Polymorphism
  • Abstraction
• Example of Java program

  • public class Mavenproject1 {

  public static void main(String[]args){

  System.out.println("Hello World!");

  }

  }
• Access Modifier


  • Keywords that restricts access to a variable, methods or classes
  • Public - Most permissive
  • Private - Most restrictive
  • Protected - Access for class and subclass
  • Default - No access modifier is specified
• Class


  • Built-in Classes - standard classes or library classes
  • Custom Class - represent specific concepts, objects, or functionalities needed in your project (building blocks you create yourself)
• Class Header


  Specifies the class header with the name Mavenproject1 as the class name
• Method Header

  public static void main(String[]args)
• Static vs. Non-Static

  • Static Method - It is associated directly to the class itself, Can be called directly without creating an object of a class
  • Non-Static Method - Also called Instance Method, Need to create an object of the class in order to access it
• Data Types - void


  It signals that there will be a data to be returned once the method is done executing
• Method name - main


  The main method in java is always named main. Since this is where the program always starts
• (String[] args)


  This is an array of type java. A string class that accepts zero or multiple arguments
• Escape Sequence


  Character combinations consisting of a backslash (\) followed by a letter or by a combination of digits, regarded as a single character and is therefore valid as a character constant.
• Sample of Simple Addition Program


  • import java.util.Scanner;

  public static void main(String[] args) {

  int num1, num2, sum;

  Scanner scanme = new Scanner (System.in);

  System.out.println("Enter first Number: ")

  num1 = scanme.nextInt();

  System.out.println("Enter second Number: ")

  num2 = scanme.nextInt();

  sum = num1 + num2;

  System.out.println("The sum is: " + sum);

  }
• Import


  Keyword that is used to include classes or packages from other files or libraries into your program. You can use its methods, fields, and other members in your code without having to fully qualify the class or package name each time you reference it.
• Package


  Mechanism for organizing related classes and interfaces into a single namespace. Essentially a folder or directory that contains a set of related Java classes and interfaces.
• Class - Scanner


  "class" in the case of Scanner refers to a Java built-in type that provides a way to read input from various sources such as the console or a file.
• Instantiation


  Process of creating an instance or object of a class. Serves as a blueprint or template for creating objects of that class.
• Method of Scanner Class


  Reads the next integer value from the input source
• Concatenation


  Process of combining two or more strings into a single string. Done using the '+' operator, which is also known as the concatenation operator.
• Control Structures


  Serve to specify what has to be done by our program, when and under which circumstances.
• Types of Control Structures


  • Sequential Logic
  • Selection Logic
  • Looping Statements
• Sequential Logic


  Also known as Sequential Flow, determined by the set of instructions that are delivered to the computer.
• Selection Logic


  Also known as Conditional Flow, involves a set of factors or parameters that determine whether one of several written modules will be used.
• Types of Selection Logic


  • Single Alternative
  • Double Alternative
  • Multiple Alternatives
• Looping Statements


  Allows us to execute a statement or group of statements multiple times.
• while loop


  Executes a target statement as long as a given condition is true. It tests the condition before executing the loop body.
• for loop


  Executes a sequence of statements multiple times and abbreviates the code that manages the loop variable.