TypeScript vs JavaScript: The Difference You Should Know

TS vs JS Which one is better

As a developer, if you ever got a chance to work on a web development project, you must have understood how JavaScript works. JavaScript has been in the market for many years and has become a popular scripting language in the developers’ community.

But as we know, if one technology or language is rising, there’s always an alternative option that is stepping into the market and giving a tough competition to the top one. And here’s a new competitor in the town – TypeScript. With the increased popularity of TypeScript, we can consider it an enhanced version of JavaScript with extra features.

Talking about TypeScript, it’s an open-source programming language for developing large-level applications. TypeScript was developed by one of the tech giants – Microsoft, in 2012. The actual reason behind this TypeScript development was to handle large-scale applications.

Moreover, Angular is also using TypeScript for web development services. As per the study, around 60% of JavaScript developers already use TypeScript, and 22% would like to implement it. Do you know why?

Actually, JavaScript is considered the primary scripting language for apps and web pages. Therefore, now, we can use JavaScript for both frontend and backend with Node.Js and Deno frameworks.

But the actual question coming now is, was JavaScript developed for creating large and complex web apps? I guess the answer is NO!

In this article, we are going to compare these two programming languages – TypeScript vs JavaScript, how they relate to one another, their differences, and outline the advantages of each.

But before that here’s a quick sneak peak of the differences between TypeScript and JavaScript in this video.

TypeScript vs JavaScript: The Real Differences

If we consider both – TypeScript vs JavaScript, then every JavaScript code is valid in TypeScript. This means TypeScript is a superset of JavaScript.

In another way, we can say,

JavaScript + more features = TypeScript

So, if you save your JavaScript programming file (.js) with a TypeScript (.ts) extension, it will execute perfectly fine. But that doesn’t mean that both languages – TypeScript and JavaScript are the same.

So, before going further in-depth, let’s understand the basic definition of each language. Here is the data from Google Trends showing the past one-year search trends of both the Frontend languages.

Why was TypeScript Developed Despite Having JavaScript?

JavaScript language was introduced as a client-side programming language. But with the usage of JavaScript for web development, developers learned that it could also be considered a server-side programming language.

However, the JavaScript code became quite complex and heavy, too. Therefore, JavaScript could not be able to stand up to the expectations of an object-oriented programming language. As a result, JavaScript will never flourish as a server-side technology in the industry. This is why the TypeScript language was born to bridge this gap.

What’s TypeScript?

Developed and maintained by Microsoft, TypeScript is an object-oriented, open-source programming language. It’s a superset of JavaScript, containing optional typing. Also, it compiles to plain JavaScript.

In a nutshell, TypeScript is a statically compiled programming language for writing clear and concise JavaScript code. It’s fulfilling the same purpose as JavaScript and can be used for both client-side and server-side applications. In addition, the libraries of JavaScript are also compatible with TypeScript.

Understand Typescript

TypeScript is a programming language that supports both dynamic and static typing. It provides classes, visibility scopes, namespaces, inheritance, unions, interfaces, and many other features. Also, it offers comments, variables, statements, expressions, modules, and functions.

You can execute it on Node.Js or any other browser that supports ECMAScript 3 or its latest versions.

Since TypeScript is an enhanced version of JavaScript, all code of JavaScript is syntactically valid TypeScript. However, it doesn’t mean the TypeScript compiler can process all JavaScript:

let a = 'a';
a = 1; // throws: error TS2322: Type '1' is not assignable to type 'string'.

TypeScript provides files that can include type data from current object files, similar to how C++ header files define the creation of current object files. Hence, other apps can use the values defined in files just as TypeScript entities with statically typed values.

You will also find third-party header files for popular libraries like jQuery, D3.js, and MongoDB. There are also TypeScript headers for NodeJs elementary modules, which allow Node.Js development within TypeScript.

The compiler of TypeScript is assembled in JavaScript and written in TypeScript. It’s registered under Apache License 2.0.

After going through the TypeScript introduction, you must be wondering what would be the objective of adding static typing to JavaScript?

Well, we can clarify your doubts with the given statements:

  • You can avoid hidden-ninja errors like the classic ‘undefined’ is not a function.

  • Easy to refactor code without breaking it significantly.
  • Orienting oneself in large-scale, complex systems is no longer a nightmare.

As per the study, TypeScript identifies around 15% of all JavaScript errors.

The freedom of dynamic typing frequently leads to errors, which not only reduces the developer’s efficiency but also can grind development due to the increasing expenses of adding new lines of code.

As a result, JavaScript is a poor choice for server-side code in organizations and large codebases due to its lack of types and compile-time error checks.

As their tagline suggests, TypeScript is JavaScript that scales.

Why Do We Need to Use TypeScript?

As we said earlier, TypeScript is an enhanced version of JavaScript. Therefore, while comparing it with other languages like CoffeeScript (which adds syntactic sugar) or PureScript (which is not similar to JavaScript at all), it’s necessary to learn many things to write TypeScript code.

Experience with TypeScript

In TypeScript, types are optional, and any JavaScript file is a valid TypeScript file. While the compiler will notify you if any of your initial files have type issues, it will still provide a JavaScript file that works. TypeScript will stand up to expectations, and it’s simple to improve your skills over time.

Is TypeScript Suitable for Frontend or Backend?

Since TypeScript is compiled to JavaScript, it is suitable for both the frontend and backend of app development.

Besides, JavaScript is a preferred programming language for the frontend of web pages and apps. As a result, TypeScript may be used for the same reason, but it also works well on the server-side for complicated and large-scale enterprise projects.

However, you can also use other top frontend frameworks like React, Angular, Vue to build next-gen apps.

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Types of TypeScript

TypeScript contains various basic types, such as Number, Array, Tuple, Boolean, String, and many more. Well, some of these types are not available in JavaScript. However, you can learn more about them in TypeScript documentation.

Furthermore, below are some other types which are expressivity of TypeScript:

Any & Unknown

A type called Any (anything that you wish) can cover unknown is its type-safe system. Here, any allows you to assign and JavaScript variable whenever you want to escape the type system. It’s widely used to describe incoming variables that haven’t been validated yet and whose type is unknown (for example, from third-party APIs).

Unknown is similar to Any, but it will not allow you to do anything with it unless it’s explicitly type-checked.?

Void

When there is no value returned, Void is used. Generally, it’s used for the return type of function that returns nothing.

Never

Never is the return type for something that should never happen, such as an exception-throwing function.

Intersection & Union Types

These types allow you to create custom types as per the logic.

Intersection types let you combine several basic types into one type. For example, if we create a custom type Person that contains first_name:string and a last_name:string. Well, you can say this as: I want my type to be this and that.

Union types allow you to type to take one of the various basic types. For example, if there’s a query that returns either result:string or undefined, you can say this as: I want my type to be this or that.

All of these sorts make sense when you think of them as spaces.

Types of TypeScript

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’re using.

On the other hand, writing them explicitly 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

With the advanced features of TypeScript, it supports additional features of JavaScript, such as object-oriented programming concepts, JS libraries, platform independence, etc.

Compatibility

TypeScript supports both old and new additional features as well. However, it’s compatible with all the versions of JavaScript, like ES7 and ES12. It can compile the completed code in ES7 back to ES5 and vice versa. This makes sure to have a smooth transition and language portability.

Static Typing

Static Typing means wherein the developer has to declare the variable type.

Suppose we take variable name str. The code will not run until you give it a type, such as an Integer, Float, List, or anything else. And TypeScript is statically typed.

Static Typing helps you with early bugs detection, faster code completion, and more.

Now, allow us to give you other prominent features here:

  • It’s easy to maintain and boosts project productivity.
  • Feasible to use static typing and annotations
  • Supports object-oriented features such as interfaces, inheritance, and classes
  • Debugging is simple, and problems are detected at an early stage.
  • Supports ES6 (ECMAScript), which provides a simpler syntax for handling objects and inheritance.
  • Full-featured IDE support

Advantages of TypeScript

TypeScript offers various advantages which could help you write a better programming language for web development.

Language Features

Here are other features that TypeScript supports.

  • Namespaces
  • Interfaces
  • Null Checking
  • Generics
  • Access Modifiers

Optional Parameters

// -- TypeScript -- //
function log(message: string = null) { }
// -- TypeScript compiled output -- //
function log(message) {
if (message === void 0) { message = null; }
}
// -- JavaScript with Babel -- //
function Log(message = null) { }
// -- Babel compiled output -- //
"use strict";
function Log() {
var message = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : null;
}

Classes

// -- TypeScript -- //
class Article {
name: string;
constructor(name: string) {
this.name = name;
}
}
// -- TypeScript compiled output -- //
var Article = /** @class */ (function () {
function Article(name) {
this.name = name;
}
return Article;
}());
// -- JavaScript with Babel -- //
class Article {
constructor(name) {
this.name = name;
}
}
// -- Babel compiled output -- //
"use strict";
function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
var Article = function Article(name) {
_classCallCheck(this, Article);
this.name = name;
};

What’s JavaScript?

JavaScript – a scripting language, is used to develop interactive web pages. It adheres to the rules of client-side programming; hence, it executes seamlessly in the user’s web browser. However, you can use JavaScript with other technologies like XML and REST APIs.

The primary purpose of JS was to make it a complementary scripting language, similar to how Visual Basic is to C++. However, JavaScript is not suitable for large-level complex applications. It was aimed to write only a few hundred lines of code for an app.

Here are some unique features that JavaScript offers:

  • Flexible, dynamic, and cross-platform
  • It can be used for both client-side and server-side
  • Lightweight interpreted
  • All browsers support
  • Weakly typed
  • JIT compilation
Robust Capabilities of JavaScript

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Difference Between TypeScript and JavaScript

While comparing two programming languages – TypeScript and JavaScript, we have to consider many factors, which are as below:

1) Learning Curve

TypeScript is a superset of JavaScript. To write a TypeScript code, you should have a basic understanding and knowledge of JavaScript. Besides, you should be clear with the OOPS concept as well.

On the other hand, JavaScript is a popular and easy-to-learn scripting language. Many developers use JavaScript with CSS and HTML to create web applications. However, HTML is tough as it contains event handling, web behavior, animations, and scripting.

2) Developers Community

TypeScript gained its popularity in a short time and was implemented by many enterprises. You will find many tutorials and guides available on the Internet to learn TypeScript. However, it has a very active and supportive community.

On the flip side, JavaScript doesn’t have a large community as compared to TypeScript. JavaScript offers many libraries, frameworks, and code practices. Therefore, it’s advisable to know your web development team structure that best suits your business needs for overall team performance.

3) Performance

As we know, TypeScript was created to overcome the challenges of JavaScript for large-level complex applications. Hence, TypeScript saves development time and allows developers to become more efficient.

The only difference between TypeScript and JavaScript is that TypeScript code is compiled into JavaScript before execution.

4) Syntax

TypeScript offers variable declaration, functional paradigm, and type system, which JavaScript doesn’t offer. It’s similar to JScript and .Net in terms of syntax, with support for ECMAScript 2015 Standard features including modules, an arrow function syntax, and classes.

JavaScript follows the ECMAScript definition as well. However, it’s not a typed language like TypeScript. It uses many structured programming terminologies from C, like if statements, switch statements, do-while loops, and many more. It offers event-driven style, functional and imperative programming.

5) Tools and Frameworks

Since Microsoft backs TypeScript, it has many leading frameworks and editors. Through tight integration with editors, it provides error handling during compilation to avoid errors at runtime.

On the flip side, there are many JavaScript frameworks available in the market for web development project requirements. It’s a huge ecosystem that’s quite popular among programmers. You can quickly find developers who specialize in ReactJS, VueJS, Angular, and other frameworks.

6) Code

For TypeScript:

class Person
{
  private name: string;
  constructor (private name: string)
  {
    this.name = name;
  }
  name()
  {
   return “name is “ + this.name;
  }
}

For JavaScript:

var Person = (function()
{
  function Person(personName)
  {
    this.name = personName;
   }
Person.prototype.name= function()
  {
    return "My name is " + this.name;
}
return Person;
})();

How does TypeScript Differ from JavaScript?

We know that TypeScript offers more features than JavaScript. In a nutshell, TypeScript is an object-oriented programming language, whereas JavaScript is a scripting language. Thus, TypeScript offers interfaces and modules through ES6 features; on the other hand, JavaScript doesn’t offer such features.

Actually, some developers may get confused between object-oriented and functional programming languages. However, you can distinguish between functional programming vs objected-oriented programming language here and know how it differs from each other.

Why Migrate Your Project to TypeScript?

If you have a large and complex codebase, there are higher chances of errors occurring. However, that would be good if some errors were resolved during the compilation time. This is when you can use TypeScript to reduce errors during compile time. The best part is that the complete Java codebase may be reused as-is.

When to Choose: Difference Between JavaScript and TypeScript

TypeScript

Compile Time Type Checking
With Vanilla JavaScript, type verification is performed at runtime. However, this adds to the runtime overhead, which may be avoided by conducting compile-time validation.
Huge Projects or Multiple Developers
TypeScript runs seamlessly for large projects or when many developers are working together.
Easy to Work with
New Libraries or Frameworks
Suppose, if you are working with React for the development and are not familiar with its APIs, you can get IntelliSense that will help you identify and navigate new interfaces. However, they both offer type definitions.

JavaScript

Small Projects
TypeScript may be overkill for small projects with fewer codes.
Framework Support
If TypeScript doesn’t support the choice of your framework – EmberJS, then you may not be able to leverage its features.
Build Tools
To generate the final JavaScript to be run, TypeScript requires a build step. However, developing JavaScript applications without the use of any build tools is becoming increasingly unusual.
Testing Workflow
If your talented JavaScript developers are already using test-driven development, the benefits of switching to TypeScript may not be enough to justify the expenditures.

Should I learn JavaScript or TypeScript?

Well, if you are aware of JavaScript, then it’s easy for you to understand TypeScript. They both languages share the same syntax and run-time behavior.

Being the most popular language, JavaScript offers many resources and a massive developers community. Since both languages are executed in the same way in many cases, TypeScript developers can also benefit from those resources.

Robust Capabilities of JavaScript

Want to Create Feature-rich yet Lightweight Apps

Benefits of TypeScript Over JavaScript

  • TypeScript supports static typing. This means that static typing allows type accuracy to be checked at build time.
  • At the time of development, TypeScript identifies the compilation bugs. As a result, the scope of evaluating errors at runtime is very less. JavaScript, on the other hand, is an interpreted language.
  • TypeScript is just JS with some extra functionality, namely ES6 features. The TS compiler can compile .ts files into ECMAScript, albeit it may not be kept in your chosen web browser.

Will TypeScript Replace JavaScript?

Well, the shortest answer to the above question is NO!

While talking about TypeScript, it is a completely different language except that it inherits the basic nature of JavaScript. Therefore, JavaScript can’t or will not be replaced ever.

JavaScript is one of the popular and fundamental technologies in the software development industry, used by a plethora of developers for both client-side and server-side.

TypeScript, on the other hand, does not execute in web browsers directly. It transcompiles to JavaScript. JavaScript is easier to debug and compile as it executes directly in the web browser. However, TypeScript is not developed for all types of projects. Therefore, both programming languages have their pros and cons along with a set of characteristics. And to walk along with enterprise web development trends, you have to adopt a new technology or framework for better business processes and customer experience.

TypeScript and JavaScript share many similarities in developing interactive web pages. While providing the head-to-head comparison of TypeScript vs JavaScript, we can say that JavaScript is a lightweight interpreted and dynamic language which is used for augmenting HTML web pages.

On the other hand, TypeScript is an enhanced version of JavaScript. This means TypeScript is a combination of JavaScript and some other traits.

Let’s understand the vital differences in the below comparison table on TypeScript vs JavaScript.

ParameterTypeScriptJavaScript
Developed ByMicrosoft in 2012Brendan Eich (Netscape) in 1995
DefinitionTypeScript is a powerful object-oriented language as a superset to JavaScript, with generic and JS features to overcome the complexities of JS.JavaScript is a scripting language with first-class functions to create dynamic web pages.
TypingStrongly Typed. TypeScript supports both static and dynamic typing.Loosely typed. JavaScript supports only dynamic typing.
EcosystemTypeScript is more of a powerful and intuitive language that supports static typing.JavaScript is a simple language that optimizes code for compatibility, easy to read and write.
CompilationTypeScript needs to be compiled.JavaScript does not need compilation.
Data BindingTypeScript utilizes concepts like interfaces and types to define the data being employed.No such notion is presented in JavaScript.
Learning CurveTypeScript has a stiff learning curve. Also, it needs scripting knowledge.It is easy to learn and a flexible language for writing web scripts.
Npm PackagesWith Typescript, numerous npm packages either have static type definitions or have an exterior one that is simpler to install.JavaScript provides the alternative to search and form code without any build step.
Client-Side or Server-SideTypeScript is specially used on the client-side.JavaScript is used on both server-side and client-side.
Files Extensions.tsx and .ts.js
CommunityTypeScript has a smaller community of software developers.JavaScript has a large community of software developers.
PrototypingPrototyping feature is available in TypeScript.JS doesn’t support prototyping.
Companies and WebsitesAsana, Clever, Screen awardAirbnb, Codecademy, Instagram
Code Examplefunction multiply (a, b)
{
return a*b;
}
var result = multiply(a, b);
console.log(‘The answer is – ’ + result);
<script>
function multiply (a, b)
{
return a*b;
}
var result = multiply(a, b);
document.write (‘The answer is – ’ + result);
</script>

Robust Capabilities of JavaScript

Still Not Sure on What to Choose for Your Next Project?

Conclusion

In the end, after going through all the insights we have curated in this article, we can say that both languages have pros and cons.

TypeScript is suitable for developers who want to create readable code that is neat and clean. Well, we are not mentioning what TypeScript offers are, including various live-bugs checking, and static typing.

Although JavaScript is not a comprehensive programming language, it can be used with HTML to improve the quality of web pages. Moreover, you will find many experienced developers who are proficient in JavaScript coding.

However, TypeScript, like JavaScript, is not supported by all web browsers. So, if you are in a dilemma of choosing between TypeScript vs JavaScript, you can refer to the above article.

Still not sure which one to choose?

Don’t worry! You can contact the experts from a leading front end development company, Radixweb, and get a free consultation who will help you understand choosing the suitable technology and language for your project requirements. Don’t wait for anymore. Contact us right now!

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A master communicator and strategist, Nihar Raval renders his services as Business Development Manager at Radixweb. Here he leads sales service verticals across geo-locations ranging from enterprise application development to performance assessment to enterprise mobility solutions to cloud migration strategies and much more. In his free time, Nihar enjoys a good informative read and loves watching and playing multiple sports.