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What is the difference between JavaScript and TypeScript?

Published On: February 21, 2024

What is the difference between JavaScript and TypeScript?


When it comes to learning about two programming languages, taking a holistic approach is vital. So, in this blog, not only will you learn about the differences between JavaScript and TypeScript but also about JavaScript and TypeScript individually, such as topics like their history, features, and more. JavaScript and Typescript are different and related at the same time; hence, exploring the differences can be a bit complex, so you will also learn about how they are related to each other. Typescript, being a statically typed superset of JavaScript, has its own features and some similarities to Javascript too. You have made a great decision by clicking on this blog, Have a great learning experience. Visit the SLA Institute to learn everything about the courses and training we offer for you. 

How are JavaScript and Typescript related?

  • TypeScript shares much of its syntax with JavaScript, ensuring that any valid JavaScript code is also valid TypeScript code. However, TypeScript expands upon JavaScript by introducing new features and syntax while ensuring compatibility with existing JavaScript codebases.
  • Unlike JavaScript, TypeScript requires compilation before execution. The TypeScript compiler (tsc) converts TypeScript code into equivalent JavaScript code, enabling it to run in any browser or JavaScript runtime environment.
  • One significant difference between JavaScript and TypeScript is TypeScript’s optional static typing. While JavaScript is dynamically typed, TypeScript allows developers to specify types for variables, function parameters, return types, and more. This feature helps in error detection during development and enhances code documentation.
  • TypeScript further streamlines development with its type inference system, which automatically deduces types based on context. This reduces the need for manual annotations, resulting in more concise code.
  • Despite its enhancements, TypeScript remains compatible with JavaScript. It serves as a superset of JavaScript, facilitating the gradual migration of JavaScript codebases to TypeScript. This compatibility enables seamless integration with existing JavaScript libraries, frameworks, and tools, empowering developers to leverage the full JavaScript ecosystem.
  • TypeScript extends JavaScript with features such as static typing, interfaces, classes, enums, and more, fostering the creation of maintainable, scalable, and error-resistant code. Developers can opt for TypeScript to enhance their development experience while retaining access to the extensive JavaScript ecosystem.

Features of JavaScript

JavaScript, recognized as a versatile programming language, presents a variety of features that make it a favored choice not only for web development but also for a wide spectrum of applications. Below are some prominent features of JavaScript:

  • Dynamic Typing: JavaScript adopts dynamic typing, enabling variables to accommodate values of any data type without the need for explicit type declarations. This trait promotes coding simplicity, even though it necessitates meticulous attention to type coercion.
  • Prototype-based Inheritance: Departing from traditional class-based inheritance, JavaScript relies on prototype-based inheritance. Objects have the ability to directly inherit properties and methods from other objects.
  • First-class Functions: In JavaScript, functions enjoy the status of first-class citizens, permitting them to be assigned to variables, passed as arguments, and returned from other functions. This capability facilitates the implementation of functional programming paradigms and higher-order functions.
  • Closures: JavaScript supports closures, empowering functions to retain access to variables from their enclosing scope even after the parent function has concluded execution. Closures are often made to establish private variables and encapsulate functionality.
  • Asynchronous Programming: Asynchronous programming forms a cornerstone of JavaScript, powered by mechanisms like callbacks, promises, and the async/await syntax. This asynchronous capability facilitates non-blocking execution, which is important for efficiently managing I/O operations in web applications.
  • Event-driven Architecture: JavaScript operates on an event-driven model, responding to user interactions and system events. Event listeners enable developers to craft interactive and responsive web applications.
  • DOM Manipulation: JavaScript is extensively utilized for manipulating the Document Object Model (DOM) of web pages, facilitating dynamic updates and interactions. DOM APIs furnish methods for accessing and modifying HTML elements, styles, and attributes.
  • Client-side scripting: Primarily executed on the client side, JavaScript enables the provision of interactive web functionality directly within the user’s browser. This approach diminishes server load and heightens the user experience by reducing page reloads.
  • Cross-platform Compatibility: JavaScript enjoys broad support across all major web browsers, rendering it a cross-platform language for web development. Moreover, technologies such as Node.js extend JavaScript’s utility to server-side environments, broadening its applicability beyond the browser.
  • Rich Ecosystem: JavaScript boasts an extensive ecosystem comprising libraries, frameworks, and tools that expedite development and enrich functionality. Esteemed frameworks like React, Angular, and Vue.js streamline the creation of intricate web applications.

Recommended read: Polymorphism in OOPs

Features of Typescript

  • Static Typing: With TypeScript, developers can define types for variables, function parameters, return values, and other elements. This feature aids in the detection of type-related errors during development and enhances code documentation.
  • Type Inference: TypeScript incorporates a powerful type inference mechanism that deduces types based on context, even if they’re not explicitly stated. This diminishes the necessity for developers to manually annotate types, resulting in more brief code.
  • Interfaces and Classes: TypeScript embraces object-oriented programming concepts like interfaces and classes, empowering developers to create custom data types and structures.
  • Enums: TypeScript offers support for enumerations (enums), enabling developers to define named constant sets. This enhances code readability and maintainability by assigning meaningful names to values.
  • Generics: TypeScript facilitates the use of generics, allowing developers to craft reusable code components compatible with various data types. Generics prove particularly beneficial when working with collections or abstract data structures.
  • Decorators: TypeScript provides decorators, a metadata type that can be attached to classes, methods, or properties. Decorators are frequently employed in frameworks such as Angular to supplement metadata and extend functionality.
  • JavaScript Compatibility: TypeScript is intentionally engineered as a superset of JavaScript, meaning that any valid JavaScript code is equally valid TypeScript code. This seamless compatibility facilitates the gradual migration of existing JavaScript projects to TypeScript.

Recommended read: What are the different data types in JavaScript?

History of JavaScript

  • JavaScript, often abbreviated as JS, originated from the work of Brendan Eich at Netscape Communications Corporation in 1995. Initially named Mocha and later LiveScript, it eventually settled on JavaScript, a move aimed at leveraging the popularity of Java during that period. Despite the name similarity, it’s important to note that JavaScript and Java are distinct languages with differing syntax and functionalities.
  • Originally conceived as a scripting language for web browsers, JavaScript aimed to introduce interactivity and dynamic behavior to web pages. Its early versions were rudimentary compared to its modern form, offering limited functionality.
  • In 1996, Netscape standardized JavaScript by submitting it to the Ecma International standards organization, leading to the creation of the ECMAScript standard. The first edition of ECMAScript was published in 1997, paving the way for subsequent editions that brought forth new features and enhancements.
  • JavaScript garnered widespread adoption among web developers due to its capability to manipulate the Document Object Model (DOM), facilitating dynamic web page interactions. The emergence of AJAX in the early 2000s further powered JavaScript’s prowess, enabling asynchronous communication between browsers and servers without necessitating page reloads.
  • In recent years, JavaScript has transcended its original role as a client-side scripting language. The advent of Node.js in 2009 extended JavaScript’s utility to server-side programming, ushering in a new era of full-stack web application development with JavaScript at its core.
  • Today, JavaScript stands as one of the most prevalent programming languages globally. Its extensive ecosystem of libraries, frameworks, and tools supports a broad spectrum of applications, including web development, server-side programming, and mobile app development. Continuously evolving with new features and updates, JavaScript solidifies its position as a foundational technology for the web and beyond.

Recommended read: JavaScript course syllabus

History of Typescript

TypeScript, an extension of JavaScript, was crafted by Anders Hejlsberg, a distinguished software engineer renowned for his contributions to Turbo Pascal, Delphi, and C#. He initiated the TypeScript project while at Microsoft, publicly unveiling it in October 2012. TypeScript emerged as a response to the challenges encountered by developers tackling extensive JavaScript projects, particularly in terms of scalability, maintainability, and tooling.

Here’s a summarized chronology of TypeScript’s development:

  • October 2012: Microsoft unveils TypeScript, positioning it as a superset of JavaScript, offering optional static typing and additional features.
  • October 2012: The inaugural public release, version 0.8, is issued, introducing crucial elements like optional static typing, classes, and modules.
  • July 2013: Version 0.9 debuts, ushering in support for generics and enhanced tooling integration with Visual Studio.
  • April 2014: TypeScript 1.0 marks its stable release, refining language syntax and tooling support.
  • July 2014: TypeScript transitions to an open-source model under the Apache License 2.0, encouraging community involvement.
  • July 2015: TypeScript 1.5 arrives, embracing ES6 features and a new compiler option for targeting ES6 output.
  • April 2016: Version 1.8 introduces support for async/await syntax and conditional types.
  • July 2017: TypeScript 2.4 adds support for dynamic import expressions and string enums.
  • March 2018: TypeScript 2.8 introduces conditional types, enhanced declaration file acquisition, and JSX support in.tsx files.
  • November 2019: TypeScript 3.7 rolls out, featuring optional chaining and nullish coalescing operators.
  • August 2021: TypeScript 4.4 debuts, incorporating advancements such as control flow analysis for destructured objects and enhanced error messaging.

Throughout its journey, TypeScript has evolved consistently, with frequent updates delivering new functionalities, refinements, and optimizations. It has garnered substantial traction within the web development community and industry, emerging as a vital tool for constructing expansive JavaScript applications. Presently, TypeScript finds widespread adoption across diverse projects, spanning web applications to server-side development with Node.js. Its thriving community and powerful tooling support position it as a preferred option for developers seeking to enhance the safety and maintainability of their JavaScript codebase.

What is the difference between Javascript and Typescript?

Type SystemDynamically typed, type checking at runtimeStatically typed, type checking at compile time
Syntax and FeaturesBasic JavaScript syntax, limited featuressuperset of JavaScript, additional features like static typing, interfaces, enums, generics, async/await syntax, decorators, and more
CompilationInterpreted by web browsers or JavaScript enginesIt requires compilation to JavaScript before execution, using the TypeScript compiler (tsc)
Tooling SupportLimited tooling supportEnhanced tooling support with TypeScript-aware editors and IDEs, providing features like autocompletion, type checking, refactoring tools, and better code navigation
Compatibility Standalone languageDesigned to seamlessly integrate with existing JavaScript codebases, facilitating gradual migration
Error PreventionLimited compile-time error checking, runtime errorsEarly error detection during compilation due to static typing, reduces runtime errors
ScalabilityChallenging to maintain large codebasesFacilitates easier maintenance and scalability of large codebases due to static typing and other features
DocumentationLacks formal type documentationProvides clearer type documentation, enhancing code understanding and maintainability
Adoption CurveLow entry barrier, quick to start codingRequires learning static typing and other TypeScript-specific features, resulting in a steeper learning curve
Code QualityMay lead to more runtime errors and debugging effortIt helps produce cleaner, more robust code with fewer runtime errors, resulting in improved code quality
Community SupportVast community support and resources are availableGrowing community support, with extensive resources and libraries, backed by Microsoft’s support and contributions
Industry AdoptionWidely adopted across industries and projectsIncreasing adoption in web development, particularly in large-scale applications and enterprise projects


Typescript is more or less the answer to all the difficulties faced while using JavaScript; this doesn’t essentially mean that typescript is superior to JavaScript or vice versa. Javascript and typescript are related and different at the same time; this is what makes the relationship complex; hence, it demands a profound and holistic understanding, which is the intention of this blog. This blog explored all the facets and aspects of both typescript and Javascript, thereby giving you an understanding that covers all aspects of both programs, which eventually makes you understand both programming languages better than ever before. 

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