10 Differences Between typescript and javascript

Differences Between TypeScript and JavaScript


JavaScript is a widely-used programming language, while TypeScript is a superset of JavaScript that adds static typing and other features. In this article, we will explore in depth what TypeScript and JavaScript are, their examples, and their uses. We will also provide a comprehensive table comparing their differences. Let’s dive in!

What is TypeScript?

TypeScript is an open-source programming language developed by Microsoft. It is a typed superset of JavaScript that compiles to plain JavaScript. TypeScript adds static typing, which allows developers to catch errors during the development process. It provides enhanced tooling and great scalability for building large-scale applications.

Examples of TypeScript

Here are a few code examples to illustrate TypeScript’s syntax and features:

// Declaring variable types
let message: string = “Hello, TypeScript!”;
let num1: number = 5;
let isDone: boolean = false;

// Functions with explicit return types
function addNumbers(a: number, b: number): number {
return a + b;

// Creating custom types with interfaces
interface Person {
name: string;
age: number;

const john: Person = {
name: “John Doe”,
age: 30,

Uses of TypeScript

TypeScript is primarily used for large-scale applications, where complex features and strict type checks are required. Some of its common uses include:

1. Building web applications with frameworks like Angular, React, and Vue.js.
2. Developing server-side Node.js applications.
3. Writing cross-platform mobile apps using frameworks like React Native.
4. Building desktop applications with frameworks like Electron.
5. Developing tools, libraries, and frameworks.

What is JavaScript?

JavaScript is a high-level, interpreted programming language that is primarily used for web development. It enables interactivity on websites and supports both frontend and backend development. JavaScript is the foundation of modern web development and is supported by all major web browsers.

Examples of JavaScript

Let’s take a look at some basic JavaScript examples:

// Declaring variables
let message = “Hello, JavaScript!”;
let num1 = 5;
let isDone = false;

// Functions without explicit return types
function addNumbers(a, b) {
return a + b;

// Creating objects
const john = {
name: “John Doe”,
age: 30,

Uses of JavaScript

JavaScript has a wide range of applications both on the client-side and server-side. Some common uses of JavaScript include:

1. Adding interactivity and behavior to websites.
2. Validating form data and performing client-side form validations.
3. Building dynamic web applications using frontend frameworks like React, Vue.js, and Angular.
4. Developing server-side applications using frameworks like Node.js and Express.js.
5. Creating mobile apps using frameworks such as React Native and NativeScript.

Differences Table

Difference Area TypeScript JavaScript
Static Typing Supports static typing, allowing type checking during development. No static typing, relies on runtime type checking.
Compilation Needs to be compiled to JavaScript before execution. Interpreted and executed directly by web browsers.
Features Includes additional features like interfaces, classes, and modules. Basic features without enhanced object-oriented programming support.
Tooling Offers strong tooling support with features like auto-completion and refactorings. Tooling capabilities vary across different IDEs and text editors.
Compatibility Compiles down to older versions of JavaScript, ensuring compatibility with older browsers. Depends on the browser’s JavaScript engine support.
Error Prevention Helps catch errors during development due to static typing. Errors can only be caught during runtime.
Code Readability Type annotations improve code readability by providing more context. Relies on variable naming conventions for readable code.
Learning Curve Slightly steeper learning curve due to additional language features. Relatively easier to learn and get started with.
Adoption Widely adopted, especially in large-scale applications. Most popular programming language, highly adopted across all web applications.
Code Execution May have a slight performance hit due to the compilation step. Direct execution results in faster performance compared to TypeScript.


In summary, TypeScript is a superset of JavaScript that offers static typing and additional features, providing developers with better error prevention and enhanced tooling support. JavaScript, on the other hand, is the foundation of modern web development and is widely used for building interactive websites and applications. The choice between TypeScript and JavaScript depends on the project requirements and personal preferences.

People Also Ask

Q: Is TypeScript a programming language?

A: TypeScript is often referred to as a programming language due to its extended features and syntax. However, it is technically a superset of JavaScript, which means that any valid JavaScript code is also valid TypeScript code.

Q: Can TypeScript run in the browser?

A: No, TypeScript cannot run directly in the browser. It needs to be compiled to JavaScript first, which can then be executed by the browser.

Q: Does using TypeScript improve performance?

A: TypeScript’s compilation step may have a slight performance hit compared to JavaScript’s direct execution. However, in real-world applications, the impact is usually negligible, and the benefits of using TypeScript often outweigh this slight performance difference.

Q: Can TypeScript code be used with existing JavaScript projects?

A: Yes, TypeScript is fully compatible with JavaScript, allowing you to gradually introduce it to an existing JavaScript codebase. You can start by adding TypeScript files alongside JavaScript files and gradually convert them to TypeScript over time.

Q: Which one should I choose: TypeScript or JavaScript?

A: The choice between TypeScript and JavaScript depends on factors like the project’s scale, team size, and personal preferences. If you are starting a new project and require strong static typing and advanced tooling, TypeScript may be a better choice. For smaller projects or rapid prototyping, JavaScript is often sufficient.

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