Module 2: Introduction to Angular Development

 Lesson 1: Installation of VS Code

Introduction


Congratulations on taking the first step into the practical realm of Angular development! In this lesson, we'll guide you through the process of setting up your development environment, starting with the installation of Visual Studio Code (VS Code). As a widely used and versatile code editor, VS Code provides excellent support for TypeScript, making it a preferred choice for Angular development.


 Why Visual Studio Code?


Before we dive into the installation steps, let's understand why Visual Studio Code is a popular choice among developers:


  1. Feature-Rich Code Editor:

   - VS Code is equipped with a plethora of features, including syntax highlighting, IntelliSense, debugging support, and Git integration.

   - It offers a smooth and efficient coding experience, essential for the development of Angular applications.


  1. Extensions Ecosystem:

   - The extensibility of VS Code is one of its standout features. A vast array of extensions is available, allowing you to customize and enhance your development environment.

   - Angular-specific extensions further streamline the development process.


 Steps to Install Visual Studio Code


Follow these simple steps to install Visual Studio Code on your machine:

  1. Download VS Code:

   - Visit the [official VS Code website](https://code.visualstudio.com/).

   - Click on the "Download for Windows" button if you are using Windows. For macOS or Linux, select the respective options.

   - Once the download is complete, run the installer.


  1. Install VS Code:

   - Follow the installation wizard instructions.

   - You can choose the default settings or customize them based on your preferences.

   - Click "Next" and then "Finish" to complete the installation.


  1. Verify Installation:

   - Open VS Code by searching for it in your applications (Windows) or using the terminal (macOS/Linux).

   - To verify the installation, create a new file and save it with a `.txt` extension. You should see syntax highlighting and other features in action.


 Lesson Recap


In this lesson, we covered the importance of Visual Studio Code in Angular development and walked through the steps to download and install it. As we move forward, having VS Code set up on your machine will be crucial for writing, debugging, and managing your Angular projects effectively.


Now, let's proceed to the next lesson, where we'll tackle another essential component of your development environment: Node.js.

Lesson 2: Setting up Node.js

Introduction to Node.js


Node.js is a runtime environment that allows you to execute JavaScript code server-side. In the context of Angular development, Node.js becomes essential for two primary purposes: package management using npm (Node Package Manager) and running TypeScript applications. In this lesson, we'll guide you through the process of installing Node.js on your machine.


 Why Node.js for Angular Development?

  1. npm - Package Management:

   - npm is the default package manager for Node.js, and it plays a crucial role in managing dependencies for Angular projects.

   - You'll use npm to install Angular CLI (Command Line Interface) and other project-specific packages.


  1. Execution of TypeScript Code:

   - Node.js allows you to run TypeScript code directly, thanks to its compatibility with JavaScript and TypeScript.

   - This is particularly important when you need to transpile TypeScript code into JavaScript before running it in the browser.


 Steps to Install Node.js


Follow these steps to set up Node.js on your machine:

  1. Download Node.js:

   - Visit the [official Node.js website](https://nodejs.org/).

   - Download the LTS (Long Term Support) version, as it provides a stable environment for development.


  1. Install Node.js:

   - Run the downloaded installer.

   - Follow the installation wizard instructions.

   - You can choose the default settings for most options.


  1. Verify Installation:

   - Open a new terminal or command prompt.

   - Type the following commands to check if Node.js and npm are installed:


     ```bash

     node -v

     ```


     ```bash

     npm -v

     ```


   - These commands should display the installed versions of Node.js and npm.


 Lesson Recap


In this lesson, we explored the significance of Node.js in Angular development, focusing on npm for package management and executing TypeScript code. By following the installation steps, you've equipped your machine with the necessary tools to efficiently manage dependencies and run Angular applications.


With Visual Studio Code and Node.js set up, you're now ready to delve into the core concepts of Angular development. In the upcoming lessons, we'll explore TypeScript fundamentals and gradually transition into building Angular applications.


Get ready to write your first lines of Angular code in Lesson 4!

 

 Lesson 3: Working with Functions

Introduction to Functions


Functions play a crucial role in any programming language, and TypeScript is no exception. In this lesson, we will dive into the intricacies of functions in TypeScript, understanding function types, parameters, return types, and leveraging them effectively in Angular development.


 Function Types


  1. Defining Function Types:

   - TypeScript allows you to define function types, specifying the parameter types and the return type.


     ```typescript

     type MathFunction = (x: number, y: number) => number;


     let add: MathFunction = (a, b) => a + b;

     ```

  1. Optional and Default Parameters:

   - TypeScript supports optional and default parameters in functions.


     ```typescript

     function greet(name: string, greeting?: string): string {

       return greeting ? `${greeting}, ${name}!` : `Hello, ${name}!`;

     }


     let result1 = greet("Alice"); // Hello, Alice!

     let result2 = greet("Bob", "Good morning"); // Good morning, Bob!

     ```


 Practical Examples of TypeScript Functions


Here is a list of TypeScript Function Examples:

  1. Callback Functions:

   - Functions can be passed as arguments to other functions, commonly known as callback functions.


     ```typescript

     function performOperation(x: number, y: number, callback: MathFunction): number {

       return callback(x, y);

     }


     let result = performOperation(10, 5, add); // Result: 15

     ```


  1. Arrow Functions:

   - Arrow functions provide a concise syntax for defining functions.


     ```typescript

     let multiply: MathFunction = (a, b) => a  b;

     ```


 Lesson Recap


In Lesson 5, we explored the intricacies of working with functions in TypeScript. Understanding function types, optional parameters, default parameters, and practical examples like callback functions and arrow functions equips you with the skills needed to write expressive and efficient code in Angular.


As we proceed, we'll continue building on these foundational concepts, gradually moving towards the practical application of TypeScript in Angular development. Stay engaged, and get ready to take your Angular skills to the next level in the upcoming lessons!

 Lesson 4: Classes and Inheritance in Angular 8

Creating a Student Class


Welcome to Lesson 6 of our Angular Development series! In this lesson, we will delve into the world of classes in TypeScript, a fundamental building block for structuring code in an object-oriented manner. We'll start by creating a basic `Student` class, exploring how to define properties such as student ID, name, email, and age.


 Walkthrough on Creating a Basic Student Class


  1. Class Declaration:

   - In TypeScript, a class is declared using the `class` keyword.


     ```typescript

     class Student {

       // class body

     }

     ```


  1. Properties:

   - Properties represent the attributes of the class. Let's add properties for student ID, name, email, and age.


     ```typescript

     class Student {

       studentID: number;

       name: string;

       email: string;

       age: number;

     }

     ```


  1. Instantiating the Class:

   - You can create an instance of the class using the `new` keyword.


     ```typescript

     let student1 = new Student();

     student1.studentID = 1;

     student1.name = "John Doe";

     student1.email = "john@example.com";

     student1.age = 20;

     ```


 Lesson Recap


In Lesson 4, we initiated our exploration of classes by creating a basic `Student` class. Understanding how to declare classes and define properties is foundational for building more complex structures in TypeScript. As we progress, we'll extend our knowledge to incorporate inheritance for enhanced code organization and reusability.

 Lesson 5: Introduction to Inheritance

Introduction: TypeScript Inheritance


Inheritance is a powerful concept in object-oriented programming that facilitates the creation of a new class by inheriting properties and methods from an existing class. In Lesson 7, we will delve into the fundamentals of inheritance in TypeScript and explore its role in promoting code reusability.


 Explanation of Inheritance in TypeScript


  1. Extending a Base Class:

   - In TypeScript, you can achieve inheritance using the `extends` keyword.


     ```typescript

     class Animal {

       makeSound() {

         console.log("Some generic sound");

       }

     }


     class Dog extends Animal {

       // Additional properties and methods specific to Dog

     }

     ```


  1. Access Modifiers:

   - TypeScript provides access modifiers like `public`, `private`, and `protected` to control the visibility of class members.


     ```typescript

     class Person {

       private age: number;


       constructor(age: number) {

         this.age = age;

       }

     }

     ```


 Demonstration of Extending a Base Class


  1. Base Class:

   - Let's create a base class `Vehicle` with a property `model`.


     ```typescript

     class Vehicle {

       constructor(public model: string) {}

     }

     ```

  1. Derived Class:

   - Now, we'll create a derived class `Car` that extends the `Vehicle` class.


     ```typescript

     class Car extends Vehicle {

       // Additional properties and methods specific to Car

     }

     ```


 Lesson Recap


This lesson provided an introduction to inheritance in TypeScript, showcasing how a class can inherit properties and methods from another class. Understanding access modifiers adds a layer of control over class members, contributing to code encapsulation.

 Lesson 6: Building a CS Student Class

Step-by-Step Guide to Creating a CS Student Class


  1. Extending the Base Class:

   Inheritance: The `ComputerScienceStudent` class is designed to build upon the existing `Student` class. By using the `extends` keyword, it inherits all properties and methods from the `Student` class. This inheritance facilitates the reuse of code and establishes a hierarchical relationship between classes, where the child class (`ComputerScienceStudent`) inherits characteristics from the parent class (`Student`).


     ```typescript

     class ComputerScienceStudent extends Student {

       // Additional properties and methods specific to CS students

     }

     ```

  1. Adding a New Property:

   - Introducing Specialized Data: Within the `ComputerScienceStudent` class, we introduce a new property, `programmingLanguage`. This property serves as a distinctive attribute representing the preferred programming language of a CS student. Incorporating such specialized properties enables more detailed and tailored representations of different entities within a program.


     ```typescript

     class ComputerScienceStudent extends Student {

       programmingLanguage: string;

     }

     ```


 Leveraging Inheritance:

  •    Promoting Code Reusability: Through the creation of the `ComputerScienceStudent` class, we practically applied inheritance. This methodology allows us to reuse existing code from the `Student` class, minimizing redundancy and promoting a more organized and efficient codebase.

  

  •    Structured Hierarchy: Inheritance establishes a structured hierarchy among classes, where attributes and behaviors are inherited and extended as needed. This hierarchy aids in creating a more modular and manageable code architecture.

 Application of Specialization:

  Customization with Specialized Properties: The addition of the `programmingLanguage` property showcases the customization and specialization potential of classes. This tailored attribute caters specifically to CS students, illustrating how classes can be adapted and enriched to represent diverse entities within a program.


By grasping the concept of inheritance and implementing specialized classes like `ComputerScienceStudent`, developers can craft more flexible, scalable, and purpose-oriented code, enhancing the versatility and maintainability of their software systems.

Lesson 7: Utilizing Constructors

Constructors Overview


Constructors play a crucial role in initializing the properties of a class when an instance is created. In Lesson 9, we'll explore the significance of constructors, especially in the context of inheritance.


 Introduction to Constructors


  1. Constructor Declaration:

   - Constructors are declared using the `constructor` keyword.


     ```typescript

     class MyClass {

       constructor() {

         // constructor body

       }

     }

     ```

  1. Super Keyword:

   - When a class extends another class, the `super` keyword is used to invoke the constructor of the base class.


     ```typescript

     class DerivedClass extends BaseClass {

       constructor() {

         super(); // Invoke constructor of the base class

       }

     }

     ```

 

 Handling Constructors in the Context of Inheritance

  1. Base Class with Constructor:

   - Let's enhance our `Student` class with a constructor that initializes its properties.


     ```typescript

     class Student {

       constructor(studentID: number, name: string, email: string, age: number) {

         this.studentID = studentID;

         this.name = name;

         this.email = email;

         this.age = age;

       }

     }

     ```

  1. Derived Class Constructor:

   - When a derived class extends `Student`, the `super` keyword is used to invoke the constructor of the base class.


     ```typescript

     class ComputerScienceStudent extends Student {

       constructor(studentID: number, name: string, email: string, age: number, programmingLanguage: string) {

         super(studentID, name, email, age);

         this.programmingLanguage = programmingLanguage;

       }

     }

     ```


This lesson emphasized the role of constructors, especially in the context of inheritance. Understanding how to initialize properties using constructors is essential for building robust and well-structured class hierarchies.


As we conclude this module, we've covered the essentials of classes, inheritance, and constructors in TypeScript. In the upcoming modules, we'll apply these concepts to Angular development, empowering you to build scalable and maintainable web applications.

Lesson 8: Creating Instances of Student Classes

Introduction


Welcome to Lesson 8 of our Angular Development series! In this lesson, we'll shift our focus to practical implementation by creating instances of the `Student` and `ComputerScienceStudent` classes. Understanding how to instantiate objects is a crucial step in applying object-oriented principles to real-world scenarios.


 Demonstrating How to Instantiate Objects


  1. Creating Instances:

   - In TypeScript, creating an instance involves using the `new` keyword followed by the class name.


     ```typescript

     let student1 = new Student(1, "John Doe", "john@example.com", 20);

     let csStudent1 = new ComputerScienceStudent(2, "Jane Smith", "jane@example.com", 22, "JavaScript");

     ```


  1. Setting Values:

   - Once an instance is created, you can set values for its properties.


     ```typescript

     student1.studentID = 1;

     student1.name = "John Doe";

     student1.email = "john@example.com";

     student1.age = 20;


     csStudent1.studentID = 2;

     csStudent1.name = "Jane Smith";

     csStudent1.email = "jane@example.com";

     csStudent1.age = 22;

     csStudent1.programmingLanguage = "JavaScript";

     ```


This lesson provided a hands-on experience with creating instances of the `Student` and `ComputerScienceStudent` classes. Understanding the instantiation process sets the stage for utilizing these objects in practical applications.

 Lesson 9: Printing Student Information

Introduction


In Lesson 9, we'll take our instantiated student objects and implement functionality to print their information. This lesson aims to showcase the inheritance feature in action, emphasizing the flexibility and code reuse inherited from the base class.


 Implementing Console.log Statements


  1. Base Class Printing:

   - Let's enhance the `Student` class with a method to print student details.


     ```typescript

     class Student {

       // ... other properties and constructor


       printDetails() {

         console.log(`Student ID: ${this.studentID}`);

         console.log(`Name: ${this.name}`);

         console.log(`Email: ${this.email}`);

         console.log(`Age: ${this.age}`);

       }

     }

     ```


  1. Derived Class Printing:

   - The `ComputerScienceStudent` class can leverage the `printDetails` method from the base class and add specialized information.


     ```typescript

     class ComputerScienceStudent extends Student {

       // ... other properties and constructor


       printDetails() {

         super.printDetails(); // Invoke the base class method

         console.log(`Programming Language: ${this.programmingLanguage}`);

       }

     }

     ```


 Showcasing the Inheritance Feature in Action


  1. Printing Student Information:

   - Now, we can use the `printDetails` method to print information for both types of students.


     ```typescript

     student1.printDetails();

     csStudent1.printDetails();

     ```


 Conclusion


As we conclude Module 5, you've gained practical insights into creating and working with instances of classes. Understanding the nuances of instantiation and leveraging inheritance for code reuse are crucial skills that will be foundational as we progress into Angular development.


Modules