TypeScript Vs JavaScript: How Do They Differ?

A well-known scripting language called Javascript has been providing the developer community with a lot of competition for a very long time. But you should be aware that anytime one language becomes more popular, another one enters the market and fiercely competes with it. This time, it’s none other than Typescript, a better-than-Javascript superset.

TypeScript is a programming language developed and maintained by Microsoft with the intent to handle large-scale applications. It is a typed superset of JavaScript that compiles to plain JavaScript, meaning that you can use any valid JavaScript code in a TypeScript file. TypeScript adds additional features to JavaScript, such as classes, interfaces, and type annotations, which can help you write more reliable and scalable code.

Here is a simple example of a TypeScript file:

In addition, Angular uses TypeScript as well for web development services. According to the report, TypeScript and JavaScript are the second and third most sought-after programming languages by developers, respectively. 

This article will take you through the similarities and differences between the two programming languages namely – Typescript and Javascript. Stay with us to know the benefits of each.

Typescript Vs Javascript – Understanding The Real Difference

Being a superset of JavaScript, TypeScript allows for the use of any valid JavaScript code in TypeScript code. However, TypeScript has additional features that are not available in JavaScript, such as interfaces and classes. These features must be compiled down to JavaScript in order to run in a browser or on a server.

The main difference between the extensions of JavaScript and TypeScript files is that TypeScript files use the .ts extension, while JavaScript files use the .js extension. But there still exist many more differences to make both languages different from each other.

Before moving forward, let’s check the Google trend for the past year’s search results for both the Frontend languages.

Source: Google Trends

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In Spite Of Javascript’s Existence, Why Was Typescript Developed?

As a language for client-side programming, JavaScript was introduced. But as JavaScript’s use in web development grew, programmers realized that it could also be thought of as a server-side programming language.

But the JavaScript code also becomes quite complex and cumbersome. As a result, JavaScript was unable to meet the requirements of an object-oriented programming language. Consequently, JavaScript will never be a widely utilized server-side technology. The TypeScript programming language was created to fill this gap.

What Is Typescript?

TypeScript, an open-source, object-oriented programming language, was developed by Microsoft as a typed superset of JavaScript, which means that it adds additional features to the JavaScript language. TypeScript was created to address some of the challenges and limitations of JavaScript, particularly in large-scale projects, and can be used for both client and server-side applications. Libraries of Javascript are also compatible with Typescript.

TypeScript is a programming language that offers both dynamic and static typing, as well as a range of features such as classes, visibility scopes, namespaces, inheritance, unions, interfaces, comments, variables, statements, expressions, modules, and functions. It can be run on Node.js or any other browser that supports ECMAScript 3 or later versions.

Since TypeScript is an extension of JavaScript, all JavaScript code is valid TypeScript code. However, this doesn’t mean that the TypeScript compiler can process all JavaScript. As an instance, the following code would produce an error:

TypeScript also provides files that can include type data from current object files, similar to how C++ header files define the creation of current object files. This allows other apps to use the values defined in these files as TypeScript entities with statically typed values. There are also third-party header files available for popular libraries such as jQuery, D3.js, and MongoDB, as well as TypeScript headers for Node.js core modules, which enable Node.js development using TypeScript.

The TypeScript compiler is written in TypeScript and compiled to JavaScript under Apache License 2.0.

So why was static typing added to JavaScript in the creation of TypeScript?

There are several benefits to using static typing in JavaScript:

• It can help prevent hidden errors such as the classic ‘undefined is not a function’
• It makes it easier to refactor code without significantly breaking it
• It makes it easier to navigate large, complex systems
• A study found that TypeScript can identify around 15% of all JavaScript errors

Dynamic typing can lead to errors and inefficiency, which can slow down development and increase the cost of adding new lines of code. As a result, JavaScript is not a good choice for server-side code in large organizations or codebases due to its lack of types and compile-time error checks. TypeScript, on the other hand, is designed to scale and address these issues.

Why Is Typescript Required?

TypeScript is an enhanced version of JavaScript, so it requires some learning to write TypeScript code, unlike languages like CoffeeScript (which adds syntactic sugar) or PureScript (which is not related to JavaScript at all). 

However, it is worth noting that types are optional in TypeScript and any JavaScript file is valid in TypeScript. While the compiler will alert you to any type of issues in your initial files, it will still produce a working JavaScript file. As you gain experience with TypeScript, it becomes easier to improve your skills over time.

Is Typescript Better For Frontend Or Backend?

TypeScript can be used for both frontend and backend development, as it is compiled into JavaScript. In addition to its use on the frontend for web page and app development, like JavaScript, it is also well-suited for use on the backend for large-scale, complex enterprise projects.

However, it is worth noting that other top frontend frameworks, such as React, Angular, and Vue, can also be used to build modern applications.

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The Types In Typescript

TypeScript has several built-in types that can be used to annotate variables and function parameters. These types help the TypeScript compiler to catch type errors and ensure that the code is correct.

Here is a list of the types in TypeScript:

• boolean – Represents a boolean value (true or false).
• number – Represents a numeric value (integer or floating point).
• string – Represents a string value.
• array – Represents an array of values. You can specify the type of elements in the array using the [] syntax. For example, number[] represents an array of numbers.
• tuple – Represents a fixed-size array with elements of different types. You can specify the types of elements in the tuple using a comma-separated list. For example, [string, number] represents a tuple with a string and a number.
• enum – Represents a set of related values. Enums are often used to define a set of constants.
• any – Represents any value. This is used when you don’t know the type of a value, or when you want to allow multiple types.
• void – Represents the absence of a value. This is often used as the return type of function that doesn’t return a value.
• null – Represents the absence of a value.
• undefined – Represents the absence of a value.
• never – Represents a value that never occurs. This is often used as the return type of function that throws an exception or never returns.

In addition to these built-in types, you can also create your own types using interfaces, classes, and type aliases.

Features Of Typescript

Some of the key features of TypeScript include:

1. Type system

TypeScript has a type system, which allows you to specify the type of a variable or function parameter using type annotations. This can help you catch type errors before the code is even run, and can make it easier to understand and work with the code.

2. Interfaces

TypeScript allows you to define interfaces, which specify the structure of an object. Interfaces can be used to enforce a particular structure for objects and can make it easier to understand how different parts of the codebase are related.

3. Classes

TypeScript supports classes, which are templates for creating objects. Classes can have properties and methods and can be extended or inherited from other classes.

4. Modules

TypeScript has a module system, which allows you to organize your code into smaller, reusable units. Modules can be imported and exported, which can make it easier to share code between different parts of your application.

5. Decorators

TypeScript has a decorator feature, which allows you to define and apply custom logic to classes, methods, and properties. Decorators can be used to add functionality or modify the behavior of a class or method.

6. JSX

TypeScript has support for JSX, a syntax extension for embedding XML-like elements in JavaScript code. This can be useful when working with frameworks like React that use JSX.

7. Compatibility

TypeScript is a superset of JavaScript, which means that any valid JavaScript code is also valid TypeScript code. This makes it easy to migrate from JavaScript to TypeScript or to use TypeScript in a project that already uses JavaScript.

8. Better tooling

TypeScript has a rich ecosystem of tools and libraries that can improve the development experience. For example, TypeScript can be integrated with IDEs and text editors to provide features such as code completion, type checking, and error highlighting.

Advantages Of Using Typescript Over Javascript

TypeScript provides various benefits that can help you write better web development code.
 In addition to its type system and other language features, TypeScript also supports-

• namespaces
• interfaces
• null checking
• generics
• access modifiers

These features can make it easier to write and maintain complex projects and can improve the scalability and maintainability of your code.

Read Also: Node.js vs React.js: Which to Choose 

What Is Javascript?

The programming language JavaScript is frequently used to develop interactive features for websites. It is a client-side language, which means that it is executed by the user’s web browser rather than on a server.

JavaScript is used to add dynamic behavior to websites, such as form validation, sliders, and dropdown menus. It is also used to create single-page applications, which are websites that load all of the necessary content and functionality in a single page rather than requiring the user to navigate to different pages.

JavaScript is a dynamically-typed language, which means that the type of a variable is determined at runtime rather than being explicitly declared. This allows for flexibility in coding, but can also make it harder to catch type errors and bugs.

Key Difference Between Typescript And Javascript

When comparing TypeScript and JavaScript, there are several factors to consider:

1. Learning curve

To write TypeScript code, you should have a basic understanding of JavaScript and be familiar with object-oriented programming concepts. JavaScript is a popular and easy-to-learn scripting language, but it can be challenging to work with HTML and CSS to create web applications.

2. Developer community

TypeScript has gained popularity quickly and has been adopted by many enterprises. It has a large and supportive community, with many tutorials and guides available online. JavaScript has a smaller community, but it offers a wide range of libraries, frameworks, and code practices.

3. Performance

TypeScript was designed to address the challenges of JavaScript for large, complex applications, and it can save development time and improve efficiency. The only difference between TypeScript and JavaScript is that TypeScript code is compiled into JavaScript before it is executed.

4. Syntax

TypeScript has a syntax similar to JScript and .Net, with support for ECMAScript 2015 Standard features such as modules, arrow function syntax, and classes. It also includes variable declaration, functional paradigm, and a type system that JavaScript does not have. JavaScript follows the ECMAScript definition and offers event-driven style, functional and imperative programming, and structured programming elements such as if statements and loops.

5. Tools and frameworks

TypeScript is supported by Microsoft and has a number of leading frameworks and editors. It integrates closely with editors to provide error handling during compilation to prevent errors at runtime. JavaScript has a large ecosystem of frameworks available, including ReactJS, VueJS, Angular, and others.

6. Code

Here is an example of a simple TypeScript program that calculates the area of a rectangle:

This code defines two number-type variables with the names width and height. Additionally, it defines a function called calculateArea that accepts the two numbers w and has inputs and returns a numerical value.

The function calculates the area of a rectangle by multiplying the w and h arguments and returning the result.

Finally, the code calls the calculateArea function, passing in the width and height variables as arguments, and stores the result in a variable called area. It then prints the result to the console using template strings.

The equivalent JavaScript code would be:

As you can see, the TypeScript code is very similar to the JavaScript code, with the addition of type annotations for the variables and function parameters.

TypeScript’s type system can help catch type errors before the code is even run, and its additional features, such as interfaces and classes, can make it easier to understand and work with large codebases. However, because JavaScript lacks a type system and is dynamically typed, these functionalities are not available in JavaScript.

Why Migrate Your Project Javascript To Typescript?

Errors are more likely to arise if your codebase is large and complex. That would be beneficial if some problems could be fixed while compiling, though. Now, TypeScript can be utilized to reduce compilation errors. The best part is that the entire Java source may be used in its current state.

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Will JavaScript be replaced by TypeScript?

Regarding TypeScript, it is a totally separate language except that it shares some of JavaScript’s fundamental characteristics. As a result, JavaScript cannot and will never be replaced.

Contrarily, TypeScript does not directly execute in web browsers. It transcompiles to JavaScript. Due to the fact that JavaScript runs directly in the web browser, it is simpler to debug and compile. But not all project types are designed for TypeScript. Thus, each programming language has advantages and disadvantages as well as a unique collection of characteristics.

Conclusion

We can conclude from the above article that both languages have their own pros and cons. Developers that wish to write understandable, and organized code should use TypeScript whereas JavaScript can be used with HTML to enhance the quality of online sites. 

However, not all web browsers support TypeScript, much like JavaScript. Therefore, if you’re having problems choosing between TypeScript and JavaScript, get in touch with Syndell, a web development company, and get a free consultation. They’ll assist you to understand and choose the appropriate technology and language for your project requirements.

FAQs

1. What is the difference between TypeScript and JavaScript?

TypeScript is a typed superset of JavaScript, which means that any valid JavaScript code is also valid TypeScript code. However, TypeScript adds additional features to the language that are not available in JavaScript, such as a type system and support for classes and interfaces.

2. Can I use TypeScript with frontend frameworks like React or Angular?

Yes, TypeScript can be used with popular front-end frameworks such as React, Angular, and Vue.js. These frameworks often have built-in support for TypeScript and provide additional features and benefits when used with TypeScript.

3. Can I use TypeScript on the backend with Node.js?

Yes, TypeScript can be used on the backend with Node.js. In fact, the TypeScript compiler itself is written in TypeScript and compiled into JavaScript.

4. Is TypeScript easier to learn than JavaScript?

It depends on your familiarity with programming concepts and languages. If you are already familiar with JavaScript, learning TypeScript may be easier because it is a superset of JavaScript and has a similar syntax. However, if you are new to programming, JavaScript may be easier to learn because it is a dynamically-typed language without a type system.

5. Is TypeScript faster than JavaScript?

TypeScript is not faster than JavaScript because it is compiled into JavaScript before it is executed. However, the type system and additional features of TypeScript can help catch errors before the code is run, which can save time and effort in debugging and testing.

6. Should I use TypeScript or JavaScript for my project?

It depends on your specific project requirements and goals. If you need a strongly-typed language with additional features such as classes and interfaces, or if you are working on a large-scale project, TypeScript may be a good choice. On the other hand, if you prefer a dynamically-typed language or if you are working on a small project, JavaScript may be a better fit.