How do you create a tsconfig.json file in a TypeScript project?

Run `tsc --init` in the project directory to generate a default `tsconfig.json` file.

What is the difference between any and unknown in TypeScript?

`any` allows unrestricted operations, while `unknown` requires type checking or narrowing before the value can be used.

How do TypeScript generics improve reusable functions?

Generics preserve the input and output type, providing safer reusable code than using `any`.

Free Course Image TypeScript Tutorial For Beginners

Free online course TypeScript Tutorial For Beginners

Duration of the online course: 4 hours and 25 minutes

New

Build safer web apps with a free TypeScript course: master types, functions, and generics, catch bugs early, and boost your JavaScript skills fast.

In this free course, learn about

Install TypeScript globally and initialize a project config with tsc --init
Understand what types are and how they enable static checking in TypeScript
Catch type errors early (e.g., invalid method calls like forEach after type changes)
Use core primitives: string, number, boolean, bigint, and their valid operations/assignments
Differentiate any vs unknown and when narrowing is required before using a value
Type objects, including optional properties using the ? modifier
Type arrays with generics, including mixed arrays like (string | number)[]
Use tuples with fixed order/length and readonly tuple behavior
Create type aliases and interfaces; know interface extension/merging advantages
Apply union (|) and intersection (&) types correctly
Define and use enums, including default numeric member values
Write typed functions: parameters, return types, anonymous and arrow functions
Use optional and default function parameters and understand their behavior
Use custom types in functions and generics to build reusable, type-safe APIs

About the free online course

If you already write JavaScript and want more confidence shipping code, TypeScript is one of the fastest upgrades you can make. This free online course helps you move from loosely typed scripts to a workflow where your editor and compiler work like a safety net, pointing out mistakes before they turn into production bugs. You will learn how TypeScript thinks, how to set it up in a project, and how to read its feedback so you can iterate quickly without guessing.

You will start by getting TypeScript installed and generating a project configuration so your code compiles the way you expect. From there, you will build a solid foundation in types, learning what they represent and why they matter. You will see how TypeScript catches common runtime problems early, such as calling array methods on values that are no longer arrays, and you will learn to lean on those checks to refactor safely.

The course then guides you through the most important everyday types you will use when building web applications: string, number, boolean, object, arrays, and tuples. You will practice choosing the right representation for real data, including optional properties and mixed collections. You will also understand when flexible escape hatches like any can hurt maintainability, and how unknown can keep safety without blocking progress.

As you advance, you will connect these building blocks into scalable models using unions, intersections, enums, interfaces, and type aliases. The focus is on writing code that stays readable as the project grows, while remaining strict enough to prevent subtle errors. Finally, you will apply TypeScript to functions, including parameters, defaults, and arrow functions, and learn how to define custom types that match your application logic. You will also learn generics so you can write reusable utilities that stay type-safe, making your codebase cleaner and easier to extend.

By the end, you will be able to add TypeScript to new or existing JavaScript projects, model data with confidence, and create functions and helpers that are both flexible and safe. If your goal is to improve code quality, reduce debugging time, and prepare for professional web development workflows, this course gives you a practical, beginner-friendly path to get there.

Course content

Video class: 01. Install Typescript Globally - TypeScript Tutorial for Beginners 04m
Exercise: Which command initializes a default TypeScript configuration file in the current project directory?
Video class: 02. Introduction to TYPES - TypeScript Tutorial for Beginners 07m
Exercise: What best describes a type in TypeScript?
Video class: 03. Catch Errors - TypeScript Tutorial for Beginners 06m
Exercise: What happens if you change an array to a number and call forEach on it in TypeScript?

Video class: 04 String Type - TypeScript Tutorial for Beginners 06m
Exercise: TypeScript strings: Which operation is valid on a variable typed as string?
Video class: 05 Number Type - TypeScript Tutorial for Beginners 06m
Exercise: Reassigning a number-typed variable in TypeScript
Video class: 06 Boolean Type - TypeScript Tutorial for Beginners 05m
Exercise: Valid assignment to a boolean in TypeScript
Video class: 07 Any Type - TypeScript Tutorial for Beginners 04m
Exercise: In TypeScript, what is the key difference between any and unknown when using a value in a function?
Video class: 08 BigInt Type - TypeScript Tutorial for Beginners 10m
Exercise: Using BigInt in TypeScript and JavaScript

Video class: 09 Object Type - TypeScript Tutorial for Beginners 08m
Exercise: How do you declare an optional property in a TypeScript object type?
Video class: 10 Array Type - TypeScript Tutorial for Beginners 08m
Exercise: Choose the correct generic syntax to declare an array that can contain strings and numbers in TypeScript.
Video class: 11 Tuple Type - TypeScript Tutorial for Beginners 09m
Exercise: TypeScript Tuples: Order, Length, and Readonly
Video class: 12 Type Aliases and Interfaces - TypeScript Tutorial for Beginners 09m
Exercise: What is a key advantage of interfaces over type aliases in TypeScript?

Video class: 13 Union Type - TypeScript Tutorial for Beginners 08m
Exercise: Choose the correct syntax to declare a variable that accepts a number or a string in TypeScript
Video class: 14 Intersection Type - TypeScript Tutorial for Beginners 09m
Exercise: Which operator is used to create an intersection type that combines multiple existing types in TypeScript
Video class: 15 Enums - TypeScript Tutorial for Beginners 05m
Exercise: TypeScript Enums: What are the default numeric values for enum members?
Video class: All About Types on Typescript - Full Tutorial 1h52m
Exercise: Choosing between any and unknown in TypeScript

Video class: 16 Functions - TypeScript Tutorial For Beginners 06m
Exercise: Create and invoke an anonymous function with typed parameters in TypeScript
Video class: 17 Function Parameters - TypeScript Tutorial For Beginners 09m
Exercise: TypeScript function parameters: optional and default behavior
Video class: 18 Arrow Function - TypeScript Tutorial For Beginners 05m
Exercise: Arrow functions: What does the fat arrow (=>) separate?
Video class: 19 Custom Types on Function - TypeScript Tutorial For Beginners 08m
Exercise: Which option correctly uses a custom type in a function as both parameter and return type, with an optional property set based on age?
Video class: 20 Learn Generics - TypeScript Tutorial For Beginners 10m
Exercise: What is the primary advantage of using generics over any in TypeScript reusable functions

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Learn aboutTypeScript

Explore free online TypeScript courses designed to help you master typed JavaScript, modern development, interfaces, generics, classes, and real-world app building. Learn at your own pace with beginner-to-advanced lessons, practical projects, and flexible study options. Enroll today, build in-demand coding skills, and earn a certificate for free.