<h2>Introduction to the course</h2><p>TypeScript is a syntactic subset of JavaScript that adds strong, static typing and compiles into plain JavaScript. TypeScript provides a wide range of features to improve user interface, introduce type aliases, tuples, generics, and so much more.</p><h2>Who is this course for?</h2><p>If you&#x27;re a developer with the basic and fundamental concepts of JavsScript down, then this course is meant for you to discover the superset of the renowned software language, JavaScript.</p>

TypeScript

<h2>What does this lesson cover?</h2><p>A module helps develop grouped functions, interfaces, classes, etc. It is executed locally, meaning whatever (gets declared in the module is inaccessible from the outside.</p><p>In this lesson, we will be declaring modules, defining and differentiating between external and internal modules, etc.</p>

Basics & Syntax

<h2>What does this lesson cover?</h2><p>Thanks to the use of the powerful type system that TypeScript provides, developers have the ability to express types in terms of other types.</p><p>How?</p><p>This lesson simply serves as an introduction to the extesnive topic that we&#x27;ll be covering in this section.</p>

Introduction

<h2>What does this lesson cover?</h2><p>This lesson will briefly introduce what object type properties are in charge of and then dive into the two main focuses of Property Modifiers: optional Parameters and read-only Parameters.</p><p>You&#x27;ll also find various examples and lesson quizzes to guide you through the world of Property Modifiers.</p>

Property Modifiers

<h2>What does this lesson cover?</h2><p>Before exploring functions even more, we find it necessary to give you a quick reminder of what we&#x27;ve learned so far. Now we&#x27;ll have a strong foundation to build on top of!</p><p>The syntax and structure of functions are crucial, after defining function creation, we&#x27;ll jump into topics such as anonymous functions and function overloads in TypeScript. </p>

Function Creation & Overloads

<h2>What does this lesson cover?</h2><p>Number objects in TypeScript (not unlike JavaScript) convert numeric literal to a number class instance.</p><p>This lesson covers String Objects as well with the methods it supports. Their usage and structure in code will be demonstrated as well.</p>

Numbers & Strings

<h2>What does this lesson cover?</h2><p>We&#x27;ll be assessing a very important term that is widely used outside of TypeScript as well as inside of it, the Type System.</p><p>Furthermore, we&#x27;ll be covering the classifications of data types in TypeScript with examples and supporting quizzes.</p>

<h2>What does this lesson cover?</h2><p>In this lesson, we&#x27;ll be assessing the connection between JavaScript and TypeScript which will foreshadow an important characteristic of TS called Portability.</p><p>We&#x27;ll thus transition into the three core components of TypeScript.</p>

<h2>What  does this lesson cover?</h2><p>Namespaces (also known as internal modules) are used to logically group related ( i.e. functions, classes, variables) code/functionality.</p><p>We&#x27;ll kick the lesson off by defining and declaring namespaces. Then we&#x27;ll focus on nested namespaces, before getting into the compare and contrast between namespaces and modules.</p>

Namespaces

<h2>What does this lesson cover?</h2><p>The strength of TypeScript&#x27;s type system is as strong as ever with the help of Generics. In simple terms, Generics permit developers to create type variables. But there is so much more to generics and we&#x27;ll be discovering it in this lesson alongside developing Generic Functions, Generic Classes, Type Aliases, etc.</p>

Generics

<h2>What does this lesson cover?</h2><p>In TypeScript applications, developers will frequently come across a type and a more detailed version of that given type. Hence, the importance of the Extending and Intersection Types.</p><p>This lesson defines the two terms mentioned above with supporting lesson quizzes and code examples.</p>

Extending & Intersection Types

<h2>What does this lesson cover?</h2><p>In this lesson, we will be referring to function parameters and return types in TypeScript.</p><p>We&#x27;ll be diving into the usage of optional parameters, default parameters, and rest parameters.</p><p>The topics mentioned will be covered individually and quite extensively with the help of lesson quizzes and code examples to guide you through the way.</p>

Parameters & Return Type

<h2>What does this lesson cover?</h2><p>Arrays and the Type interface is an important aspects of TypeScript. This lesson will demonstrate and describe the features of arrays, how to initialize them, and the different types you can choose from.</p><p>Then we&#x27;ll transition into the definition of the Type Interface and its relevance.</p>

Arrays & Type Inference

<h2>What does this lesson cover?</h2><p>Built-in types are the most common value types in JS code that will conduct type annotations in your TypeScript application. The three primitives are string, number, and boolean. Each of these JS types has its own specific type in TypeScript and we will be referencing each type separately.</p>

Built-in types

<h2>What does this lesson cover?</h2><p>After the basics, let&#x27;s jump into the installation process of TypeScript to start experimenting. There are a few ways to install TypeScript, but a few prerequisites will be touched on throughout the lesson so that you choose the route best for you and the line of work you want to pursue further.</p>

Installation

Lesson Challenge

<h2>What does this lesson cover?</h2><p>keyof and typeof operators are a method to display new types with the help of existing types/values.</p><p>In this lesson, we will be describing the two operators with their syntax, structure, and behavior in code.</p>

Keyof & Typeof Operators

<h2>What does this lesson cover?</h2><p>TypeScript is known for helping developers work in a more efficient and effective setting while avoiding mistakes and time-consuming difficulties. Generic Object Types are a perfect example of this.</p><p>This lesson defines the advantages Generic Object Types offer developers, how and when to use them, and their structure in code.</p>

Generic Object Types

<h2>What does this lesson cover?</h2><p>Combining any type of value, more than one can be conducted with Union Types. We&#x27;ll be providing code examples and further use of the term to help make it comprehensible.</p><p>Object Types are the second most common types after primitives, and it&#x27;ll be our focus for the second half of the section.</p>

Union and Object Types

<h2>What does this lesson cover?</h2><p>A variable is a named space in the memory that acts as a storage for values. JavaScript naming rules for variables are carried out in TypeScript as well.</p><p>In this lesson, we&#x27;ll be assessing the rules and regulations of variables which will lead to declaring variables and type association.</p>

Variables

<h2>What does this lesson cover?</h2><p>In this lesson, we&#x27;ll be assessing the General Rules of TypeScript to outline your future development journey.</p><p>We&#x27;ll also be referring to Object Orientation within TypeScript. By defining OOP and its significance in TypeScript.</p>

Core Concepts

<h2>What does this lesson cover?</h2><p>We&#x27;ll be covering two different topics in this lesson: Indexed Access Types and Utility Types.</p><p>These topics require hands-on examples to help new developers better understand them, therefore, the lesson in equipped with various code examples and lesson quizzes.</p>

Indexed Access Types & Utility Types

<h2>What does this lesson cover?</h2><p>In this lesson, we&#x27;ll be working towards comprehending Type Aliases, in simple terms, give a type a new name. We&#x27;ll be exploring this term and combine it with knowledge of Interfaces.</p><p></p>

Type Aliases & Interfaces

<h2>What does this lesson cover?</h2><p>We&#x27;ll be covering operators in TypeScript. There are three types of operators in TypeScript: Logical, Arithmetic, and Bitwise. </p><p>This lesson will be all about operators, their syntax, and structure in code with supporting lesson quizzes.</p>

Operators

<h2>What does this lesson cover?</h2><p>In this lesson, we&#x27;ll be guiding you on the development of your first program. To make the journey as bump-free as possible, we&#x27;ll be providing certain rules regarding syntax and structure and you&#x27;re good to go!</p>

First program

<h2>What does this lesson cover?</h2><p>To bridge the gap between the types of inputs and outputs, developers will need to incorporate Conditional Types in their code.</p><p>The aim of this lesson is to help developers learn how to declare and use Conditional Types in their code when needed.</p><p>We will also be defining Distributive Conditional Types with supporting code examples and lesson quizzes.</p>

Conditional Types

<h2>What does this lesson cover?</h2><p>TypeScript supports an extensive amount of user-defined types. Lucky for us, we&#x27;ll be covering each and every single one of them seperately and just as extensively.</p><p>User-defined types are: arrays, enums, tuples, interfaces, functions, and classes.</p>

User-defined Types

<h2>What does this lesson cover?</h2><p>Repetitions in code are a common issue many programmers deal with. Repeating code may lead to many human errors when an application gets complex not to mention it&#x27;s time-consuming and useless.</p><p>Mapped Types help developers eliminate code repetitions, and we will be discussing how to incorporate them into your code.</p>

Mapped Types

<h2>What does this lesson cover?</h2><p>Template literal types are heavily based on string literal types and with the help of unions, develop into many strings.</p><p>This lesson will help developers learn how to use and work with template literals by defining their structure, syntax, and behavior in code.</p>

Template Literal Types

The keyof Operator

<p>The TypeScript <samp><strong>keyof</strong> </samp>operator develops a numeric or string literal union of keys from an object type.</p>

<p><strong><samp>type S </samp></strong>is essentially the same type as <strong><samp>“x” | “y”</samp></strong>.</p>

<p>A more specific example would include the specification of either <strong><samp>string</samp></strong> or <strong><samp>number </samp></strong>index signatures. In that case, <samp><strong>keyof</strong> </samp>will return the defined type.</p>

<p>Similarly, with a <strong><samp>string type</samp></strong>:</p>

Write Missing

<p>Complete the code with the <samp><strong>keyof</strong> </samp>operator.</p>

<p><strong>Note:<samp> S</samp></strong> should be the same type as <strong><samp>“no” | “yes”</samp></strong>.</p>

The typeof operator

<p>With the TypeSript <samp><strong>typeof</strong> </samp>operator developers can refer to the <strong>type </strong>of variable/property by using it in a <strong>type context.</strong></p>

<p>This may seem useless for simple applications, however, by pairing the <samp><strong>typeof</strong> </samp>operator with complex applications multiple patterns can be expressed.</p>

<p>Let’s take a <samp><strong>Return&lt;T&gt;</strong> </samp>predefined type. It takes on a <strong>function type</strong> and returns a <strong>return type</strong>.</p>

<p>The problem will arise when we try to use <samp><strong>return</strong> </samp>on a function name. Since values and types are not the same things, we’ll need to refer to the type that the value of a function has, we’ll use <strong><samp>typeof</samp></strong>, like so:</p>

<p>Complete the code by referring to the type that the value <samp><strong>t</strong> </samp>has.</p>

<h2>What does this section cover?</h2><p>This section introduces newbies to the absolute fundamentals and basics of TypeScript. After defining TypeScript and its perks, we&#x27;ll identify TS characteristics such as Components and Portability.</p><p>Another area we&#x27;ll uncover is concepts of TypeScript that every developer should know.</p>

Get Started

<h2>What does this section cover?</h2><p>The core of all TypeScipt applications consists of every type, variable, and operator that you will find in this section.</p><p>We&#x27;ll get you acquainted with the Type System, which is a global term that is the representation of the myriad of values supported by TypeScript. And we&#x27;ll go from there.</p><p>With code examples, lesson challenges, and quizzes, you&#x27;ll have the perfect knowledge base to build on top of.</p>

Types Basics

<h2>What does this section cover?</h2><p>This section is a mixture of building on top of the core concepts and introducing new ones.</p><p>Just to give you an example, we&#x27;ll be getting into the Number Object, the String Object, and Methods.</p><p>Furthermore, we&#x27;ll assess Arrays, the Type Interface, Union Types, Object Types, Type Aliases, and Interfaces.</p>

Types Advanced

<h2>What does this section cover?</h2><p>Functions are a staple in the majority of programming languages. We&#x27;ll be assessing functions in JavaScript and how they work with TS.</p><p>This section covers the definition of functions, how to create them, the different types of functions, fucntion overloads and much more.</p>

Functions

<h2>What does this section cover?</h2><p>In this lesson, we&#x27;ll be getting into one of the most famous things TypeScript is known for: Object Types.</p><p>Object Types are unique because of the wholly different approach they offer when working with JavaScript. </p><p>Property Modifiers, Generic Object Types, Intersection, and Extending Types are all a part of Object Types and we&#x27;ll be getting into each and every single one of these topics extensively in this section</p>

Object Types

<h2>What does this section cover?</h2><p>This section is a perfect description of where the power of TypeScript comes from its powerful type system.</p><p>The TypeScript Type system help developers display new types with the help of existing types/values with various methods that will be individually assessed in separate lessons.</p><p>Some of them are generics, keyof, typeof, indexed access types, conditional types, template literals, and more.</p>

Type Manipulation & Generics

<h2>What does this section cover?</h2><p>Modules and Namespaces in TypeScript play a crucial role in the development of your application.</p><p>We&#x27;ll be going over the basic syntax and structure of both of them before getting to the fun part and comparing the two.</p><p>This lesson is equipped with various code snippets and lesson challenges to help users better understand the topic.</p>

Overview

The keyof Operator

The typeof operator