TypeScript vs JavaScript: The Ultimate Comparison in 2023

TypeScript vs. JavaScript: As the most popular scripting programming language for many successful projects, JavaScript is universal in IT. TypeScript is suitable for large-scale projects as an alternative option. Although similar, significant differences exist between them.


JavaScript has been a superior technology in the software development industry for over two decades. 

But it also has some problems, so another technology called TypeScript came along to fix them. What distinguishes them, and can they be used interchangeably? What are their differences? Let's find out together. 

We'll explain if JS and TS are OOP languages and which ones developers should learn. Finally, we will disclose which is better. JavaScript has contributed to the success of the web. Should TypeScript become more popular than JavaScript?

TypeScript vs. JavaScript: The Real Differences

TypeScript vs. JavaScript The Real Differences
TypeScript vs. JavaScript The Real Differences

Regarding greenfield web or Node.js projects, developers often consider TypeScript and JavaScript. But this question is just as crucial for existing projects too. TypeScript, a superset of JavaScript, offers all of JS's features and additional perks. Its clean coding practices make the code more scalable. And don't worry; you can still include plain JavaScript in your projects using TypeScript.

Although JavaScript (JS) and TypeScript (TS) share many similarities, their differences ultimately determine better. This article will explore the main contrasts between both languages and provide code examples to illustrate their disparities.

We'll investigate whether JS and TS are object-oriented programming (OOP) languages and recommend which one to learn. Which one is better? With JS being the backbone of the web, is it time for TypeScript to steal the limelight? Let's find out!

In simple terms, TypeScript is JavaScript with additional features.

JS JavaScript More Features TypeScript
JS JavaScript More Features TypeScript

Did you know you can save your JavaScript programming file (.js) as a TypeScript (.ts) extension, and it'll still work fine? However, knowing that TypeScript and JavaScript have distinct characteristics is essential.

Why was TypeScript Developed Despite Having JavaScript?

JavaScript was initially developed and introduced as a programming language for client-side use. With the widespread adoption of JavaScript, developers realized it's for server-side programming.

Nonetheless, the complexity and weight of JavaScript code hindered its progress as an object-oriented programming language.

Consequently, it needed to meet the expectations of being a server-side technology in the industry. 

Due to this limitation, they developed TypeScript language to address this gap and offer a solution.

What is TypeScript?

Whats TypeScript
Whats TypeScript

If you're wondering, "What's better than JavaScript?" the answer is TypeScript. TypeScript is an object-oriented programming language developed and maintained by Microsoft that extends JavaScript as a superset. It offers optional typing and can compile plain JavaScript code.

This compiled programming language helps developers write clean JavaScript code. TypeScript is compatible with JavaScript libraries and can be a client- and a server-side application.

TypeScript is a versatile programming language that supports dynamic and static typing. Its features include classes, interfaces, namespaces, inheritance, visibility scopes, unions, etc. Also, TypeScript supports statements, expressions, modules, functions, comments, and variables.

Node.js utilizes TypeScript or any browser that supports ECMAScript 3 or newer versions. As TypeScript improved the performance of JavaScript, all JavaScript code is valid TypeScript syntax. 

However, not all JavaScript code can process by the TypeScript compiler:

let b = 'b';

b = 2; // throws: error TS2322: Type 'number' is not assignable to type 'string'.

What TypeScript Can Provide

TypeScript provides files containing type data from current object files, similar to how C++ header files define the creation of recent object files. Consequently, other applications can use values expressed in these files as TypeScript entities with static types.

You can also find third-party header files for popular libraries such as D3.js, MongoDB, and jQuery, along with TypeScript headers for elementary modules of Node.js that enable Node.js development within TypeScript.

TypeScript compiler is implemented in JavaScript and TypeScript, licensed under Apache License 2.0. After learning about TypeScript, you may wonder about the purpose of adding static typing to JavaScript.

We can address any doubts or confusion you may have with the following statements:

  • You can prevent hidden ninja errors like the typical 'undefined' is not a function error. 
  • It also makes refactoring code easier without causing significant functionality breaks. 
  • Navigating large-scale and complex systems becomes less of a nightmare when using TypeScript.

According to research, TypeScript can detect approximately 15% of all errors in JavaScript. The flexibility of dynamic typing often results in mistakes, which can decrease a developer's productivity and increase costs associated with adding new lines of code.

Therefore, when dealing with large codebases and organizations, JavaScript's lack of types and compile-time error checks may make it a more suitable option for server-side code. However, TypeScript's tagline, "JavaScript that scales," implies that it can handle more significant and complex projects while providing the benefits of static typing.

Why Do We Need to Use TypeScript?

When compared to languages such as CoffeeScript (which introduces syntax enhancements) or PureScript (which is vastly different from JavaScript), learning TypeScript requires a broad understanding of its concepts. Note that TypeScript permits optional typing and treats any JavaScript file as a valid TypeScript file.

While the compiler will flag any typing issues in your initial files, it will still generate a working JavaScript file. TypeScript delivers on its promises, is relatively easy to learn, and enhances proficiency.

Is TypeScript Suitable for Front-end or Back-end?

TypeScript is a universal language compiled into JavaScript for front-end and back-end development. Although JavaScript is a popular choice for front-end web development, TypeScript's additional features make it a suitable alternative, especially for complex enterprise projects. 

Types of TypeScript

Types of TypeScript
Types of TypeScript

TypeScript provides several built-in types to define a program's variables, function parameters, return types, and other values. Some of the most common types in TypeScript include:

1. ‘number’: Represents numeric values, including integers, floating-point numbers, and NaN

2. ‘string’: Represents string values, including single and double-quoted strings.

3. ‘boolean’: Represents boolean values, which can be either true or false.

4. ‘object’: Represents non-primitive types, including arrays, functions, and objects.

5. ‘any’: Represents any value and can be used to disable type checking.

6. ‘unknown’: Represents unknown values at compile-time, usable post-type-checking.

7. ‘void’: Represents the absence of a value, and is used for functions that do not return a value.

8. ‘null’ and ‘undefined’: Represent null and undefined values, respectively.

9. ‘never’: Represents values that cannot occur, such as the result of a function that always throws an error or loops indefinitely.

In addition to these built-in types, TypeScript supports user-defined types, such as interfaces, classes, and enums. This creates custom data structures and provides a different kind of safety in a program.

TypeScript supports both implicit and explicit types. If you don't write your types explicitly, the compiler will enable type inference to identify the types you use. On the other hand, writing them provides benefits, such as assisting other team members who read your code and verifying that what you see is what the compiler sees.

Features of TypeScript

Features of TypeScript
Features of TypeScript

TypeScript's advanced features support JavaScript's object-oriented programming concepts, libraries, and platform independence. It also provides several features that are not available in JavaScript. Here are some of the critical elements of TypeScript:

1. Static Typing: TypeScript offers a static type system for specifying types of variables, function parameters, and return types. This helps catch type-related errors at compile time rather than run-time, leading to more robust and reliable code.

2. Type Inference: TypeScript can also infer types automatically based on the values assigned to variables and function parameters. This reduces the need for developers to specify types explicitly in many cases, making the code more concise and readable.

3. Interfaces: TypeScript supports interfaces, which define a set of properties and methods that a type must have to be considered compatible. This allows for more flexible and modular code that can work with different types of objects that share common characteristics.

4. Classes: TypeScript supports object-oriented programming (OOP) features such as classes, inheritance, and interfaces. This allows developers to write code in a more organized and reusable way.

5. Enums: TypeScript supports enums, which define a set of named constants. This makes the code more readable and self-documenting.

6. Generics: TypeScript supports generics, which allow functions and classes to work with various types without having to be rewritten for each type. This makes the code more flexible and reusable.

7. Decorators: TypeScript supports decorators, which are a way of adding metadata to classes, methods, and properties. This adds logging, validation, or caching functionality to a class or method.

8. Compatibility with JavaScript: TypeScript is a superset of JavaScript, meaning existing JavaScript code integrates easily into TypeScript projects. This allows developers to gradually introduce TypeScript into their projects and take advantage of its features without completely rewriting their codebase.

Overall, TypeScript provides a robust and flexible type system that allows developers to write more reliable and maintainable code while still retaining the flexibility and dynamism of JavaScript.

Advantages of TypeScript

Advantages of TypeScript
Advantages of TypeScript
  1. Precise Typing: TypeScript allows for precise defining via typing, ensuring that everything stays as specified by developers.
  2. Type Annotations: TypeScript provides a convenient way to express the type to use unequivocally, making code more readable and reliable.
  3. Type Inference: TypeScript developers don’t need to provide types when the compiler can find them without outside help, making code more concise and easier to write.
  4. Structural Typing: TypeScript requires a definite structure that facilitates increased safety and better code organization.
  5. Improved Team Efforts: TypeScript allows developers to focus on their work without relying on their teammates. With clearly defined data structures and type annotations, it is easier to understand developers’ decisions and introduce new members to the team.
  6. High Performance: TypeScript makes individual engineers more effective, leading to improved performance of the entire project team.
  7. Error Identification: TypeScript identifies compilation errors as soon as possible, preventing further adverse effects and facilitating a fast refactoring process.
  8. Readability: It is easy to comprehend the intention of software engineers who initially created the code, which makes collaboration more effective.
  9. Quick Updates: With TypeScript, it is easy to update or refactor apps, keeping code maintainable and up-to-date.
  10. Object-Oriented Programming Support: TypeScript supports OOP concepts, allowing developers to build well-structured and scalable code that is easy to maintain. This is particularly useful for more extensive and complex projects.

Disadvantages of TypeScript

Disadvantages of TypeScript
Disadvantages of TypeScript
  1. TypeScript's compilation process is longer than that of JavaScript, which can make it more time-consuming.
  2. There may be better options for small-scale projects, but it truly shines in large-scale, complex projects with sophisticated heavy-load architecture.
  3. The typing system in TypeScript can be intricate, making it challenging for some developers to implement it correctly. However, this is not a flaw of TypeScript but rather an interoperability issue with JavaScript.
  4. Unlike JavaScript, TypeScript requires compilation, which can add an extra step to the development process.
  5. Although TypeScript is relatively easy for JavaScript programmers to learn, it is still an additional language to master. So, if you have a team of JavaScript developers looking to start new projects in TypeScript, be aware that it involves a learning curve.
  6. While TypeScript can catch type-related errors, it's important not to assume that all code written in TypeScript is flawless. It's still essential to thoroughly test and debug your code.

What is JavaScript?

What's Javascript
What's Javascript

JavaScript is a scripting language that is commonly into developing interactive web pages. It follows the rules of client-side programming, allowing it to execute seamlessly in the user's web browser. However, JavaScript can also be with other technologies like XML and REST APIs.

Initially, JavaScript intends to be a complementary scripting language, much like Visual Basic is to C++. It was designed to write only a few hundred lines of code for an application and is unsuitable for large-scale complex applications.

Despite this, JavaScript offers several unique features, such as flexibility, dynamic capabilities, and cross-platform compatibility; JavaScript supports all browsers and weak types.

JavaScript also uses Just-In-Time (JIT) compilation, which compiles code at run-time, making it faster and more efficient than traditional interpreted languages. Overall, JavaScript is a versatile language offering many features and web development uses.

Advantages of JavaScript 

  • Fast-paced. As an interpreted language, JavaScript reduces compilation time for other languages. JavaScript is a client-side script, meaning it’s not the web server but the browser that processes the coding. Developers prefer using these scripts to validate data before sending it to the web server.
  • Simple. JavaScript is easy to understand and learn. Due to its intelligible, unambiguous structure, it is easy to grasp for both the users and developers.
  • Cost-effective. JavaScript is cheap to use, thus saving monetary resources.
  • Popular. Every popular browser supports JS, and many large companies, including tech giants like Meta, eBay, NASA, etc., use it.
  • Interoperable. JavaScript functions perfectly with other languages. For that reason, lots of engineers utilize it for their app development. JavaScript embeds into any webpage or even into scripts of different languages.
  • JavaScript has robust frameworks. As there are several corresponding frameworks for JavaScript, it significantly simplifies the developer’s job. This code is easy to read, identify, and fix errors. This helps developers enhance their programs with additional features that make the coding more efficient.
  • Versatile implementation. Using the power of Node.js servers, engineers can make the most of JavaScript and expand its potential manifold.
  • Full-stack development. JavaScript now supports both front-end and back-end development, with Node.js for the back-end and Angular, React, Vue, etc. for the front-end.
  • Concise code. Thanks to compact coding, JS can improve the functioning of web pages and apps.

Disadvantages of JavaScript 

  • Discovering errors during run-time is impossible in JavaScript, unlike TypeScript.
  • JavaScript is not ideal for large-scale projects, unlike TypeScript, which is more suited for them.
  • JavaScript coding may not consistently support across different web browsers, necessitating testing on multiple platforms. Older browsers may also need to support new functionalities.
  • Refactoring code in JavaScript can be challenging and may not effectively improve code quality.
  • Debugging and identifying errors in JavaScript code can be difficult due to ineffective debugging tools and a lack of error display.
  • A single error can terminate the rendering process of all JavaScript code on a website.

TypeScript Vs. JavaScript Comparison

Typescript vs Javascript comparison
Typescript vs Javascript comparison
Developed ByMicrosoft in 2012Brendan Eich (Netscape) in 1995
DescriptionTypeScript is a superset of JavaScript, explicitly created to overcome code complexity issues in large-scale projects.JavaScript, on the other hand, is a high-level, lightweight, and dynamic scripting programming language.
Error IdentificationAllows errors to be caught and corrected during compile-time.Allow errors recognized during run-time since it is an interpreted language.
Browser'sTypeScript code must transpile into JavaScript before its execution.JavaScript code applies directly without any additional steps.
Optional Parameters in FunctionsAchievableAchievable
TypingStrongly Typed. TypeScript supports both static and dynamic typing.Loosely typed. JavaScript supports only dynamic typing.
Project ScaleBest suited for large-scale and complex applications involving global development teams. By helping to reduce development time and improve workflows, TypeScript can significantly enhance the efficiency of such projects.Ideal for smaller-scale applications that have a clear and straightforward structure. Due to its simplicity, it is well-suited for creating compact and simple applications.
Ease of LearningPrior knowledge of JavaScript is recommended before learning TypeScript, as it is not a suitable language for beginners.JavaScript is an excellent choice for novice IT specialists to start their programming journey.
CommunityTypeScript's user community is continuing to expand and evolve.JavaScript already has a well-established, large community of developers.
AnnotationRequiredNot required
CompilationRequiredNot required
PrototypingAvailableNot supported
Known ClientsAsana, Slack, Typeform, Accenture, Clever, Screen, etc.PayPal, Airbnb, Uber, Codecademy, Netflix, Instagram, etc.
Code Sample
function addNumbers(num1: number, num2: number): number {  return num1 + num2;}
let result = addNumbers(3, 5);console.log(result); // Output: 8
function addNumbers(num1, num2) {  return num1 + num2;}
let result = addNumbers(3, 5);console.log(result); // Output: 8

Is it better to learn JavaScript or TypeScript?

is it better to learn javascript or typescript
is it better to learn javascript or typescript

If you are familiar with JavaScript, learning TypeScript should be straightforward as both languages share the same syntax and run-time behavior. JavaScript is one of the most widely used programming languages and has a vast community of developers, providing a wealth of resources. 

As TypeScript often executes similarly to JavaScript, TypeScript developers can benefit from this abundance of resources.

Can TypeScript Replace JavaScript?

Can TypeScript Replace JavaScript?
Can TypeScript Replace JavaScript?

In short, the answer to the question is no. TypeScript is a distinct programming language that inherits some fundamental characteristics of JavaScript. Despite this, JavaScript cannot and will not replace TypeScript.

While JavaScript executes directly in web browsers, TypeScript takes a different approach. It trans-compiles to JavaScript, which may make it slightly more challenging to debug and compile. However, TypeScript offers unique benefits to handle large-scale projects' complexities.

Both programming languages have pros and cons, and choosing the correct language for your project depends on your specific needs and requirements. Adopting new technologies or frameworks may be necessary to keep up with the latest trends in enterprise web development and provide the best customer experience.

Final Thoughts

After analyzing all the insights we've presented in this article, it's clear that TypeScript and JavaScript have their strengths and weaknesses.

TypeScript is an excellent choice for developers who prioritize creating clean, readable code. It offers features like live bug checking and static typing that can improve code quality and maintainability.

While JavaScript may not be as comprehensive as TypeScript, it can still be applicable with HTML to enhance web page functionality. Additionally, many experienced developers are proficient in JavaScript coding.

However, it's worth noting that not all web browsers support TypeScript and JavaScript equally. We recommend referring to this article for guidance if you need help deciding which language to choose.

If you still need to decide which language suits your project, feel free to seek advice from experts in the field. At LANEX Corporation, a leading front-end development company, you can receive a free consultation to help you choose the best technology and language for your specific project requirements. Don't delay - contact us today!

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