TypeScript

TypeScript makes JavaScript developers work smarter

JavaScript is the single most popular programming language on the planet. Why? Because every company in the world has come to realize websites are a necessity for doing business. And to draw and keep users coming back to your site, you need to make that site as interesting and interactive as possible. With JavaScript, that’s not only possible – it’s easy.

JavaScript is a text-based programming language designed for both client- and server-side that allows developers to make web pages interactive and exciting. JavaScript can be used for:

Client-Side Web Applications
Server-Side Web Applications
Mobile Applications
Desktop Applications
Web Games

It’s because of the use-cases listed above that JavaScript has become the hottest language on the planet. But JavaScript does have its limitations. For example, as JavaScript codebases grow, they tend to get messy and challenging to maintain, which means code isn’t always easily reusable. In today’s modern world of program development, reusable code makes for less work. And every software engineer should be thinking about working smarter, instead of harder.

TypeScript is generally thought of as JavaScript for application development at scale. It’s a strongly-typed, object-oriented, compiled superset of JavaScript. Think of TypeScript as a super-charged version of JavaScript.

Because TypeScript fully embraces object-oriented programming, strong type checking, and compile-time error checks, it makes JavaScript a much more viable language for enterprise-class businesses.

TypeScript Developers Hiring Guide

How to choose the best
Interview questions
Job Description

From humble beginnings

TypeScript was created by Microsoft and first released in October 2012. Back then, it was criticized as immature, because of a lack of IDE support (outside of Microsoft Visual Studio). It took quite some time, but eventually, TypeScript found support in other IDEs and text editors across platforms (such as Linux and macOS).

Currently, the list of IDEs that support TypeScript includes:

Visual Studio Code
alm.tools
JetBrains
Atom
Cloud9 IDE
Eclipse IDE (via a plugin)
Codeanywhere
Angular IDE
Tide

With the help of plugins, TypeScript can be integrated with automation tools like Grunt, Apache Maven, Gulp, and Gradle.

Originally designed to overcome JavaScript’s inability to work with large-scale application development, the original developers sought a solution that wouldn’t cause compatibility issues and standards. To help bridge TypeScript and JavaScript, the developers created a JavaScript compiler that included a set of syntactic language extensions, which can transform the TypeScript extensions into standard JavaScript.

TypeScript Features

The features of TypeScript make it appealing to companies looking to implement JavaScript-like functionality but on a large scale. Those features include:

TypeScript is really just JavaScript, so all of those JavaScript developers on your payroll, shouldn't have any problems adapting to this language.
Supports JavaScript libraries. TypeScript supports all of the existing JavaScript frameworks, libraries, and tools, so your developers should already have most of the skills they need to get started.
Portability. TypeScript is portable across all browsers, devices, and operating systems. In fact, any environment that supports JavaScript will support TypeScript.
TypeScript allows the optional chaining operator (?.) which enables developers to read the value of a property located deep within a chain of connected objects.
DOM manipulations. TypeScript can be used to manipulate the DOM for the adding or removing of elements (in a similar fashion to JavaScript).

Why should you employ TypeScript?

There are several reasons why your business should be making use of TypeScript, such as:

Typescript supports static typing.
TypeScript supports ECMAScript 2015 classes.
TypeScript supports generic programming.
TypeScript makes JavaScript code easier to read and debug.
TypeScript is open source, so it enjoys a large community and several open-source frameworks and libraries.
TypeScript enjoys all the benefits of ES6 (ECMAScript 6) and adds even more productivity features.
TypeScript helps developers to avoid common JavaScript bugs by checking the code as they type.
TypeScript includes a powerful type system (including generics).
TypeScript is a structural language, rather than a nominal one.
TypeScript code can be compiled according to ES5 and ES6 standards, so it supports all of the latest browsers.
TypeScript code is easier to understand than JavaScript.

The components of TypeScript

TypeScript is comprised of the following 3 components:

The TypeScript language - syntax, keywords, and type annotations.
TypeScript compiler - converts the instructions written in TypeScript to the JavaScript equivalent.
TypeScript Language Service - exposes an additional layer around the compiler pipeline to support the common set of standard editor operations (such as statement completion, signature help, formatting, and syntax highlighting).

TypeScript Hiring Guide

Hiring Guide
Interview Questions
Job Description

TypeScript: A Summary

TypeScript, a portable, cross-platform, open-source language is essentially a tweaked version of JavaScript. In fact, it’s translated into JavaScript during its execution. Using all the same components as its parent language, TypeScript is accessible to engineers who understand and use JavaScript, too.

Developers can take advantage of all JavaScript tools, including libraries, JS frameworks, and more. TypeScript can run on any JavaScript-supported environment. Like its parent language, it can be used for both frontend and backend development.

That said, it has a number of benefits that elevate the language. For example, it has the addition of static typing, which makes it more readable. It’s also considered more expressive than JavaScript. Additionally, it’s very easy to debug thanks to a high-level debugger.

What to Look for in a TypeScript Developer

First things first: any TypeScript developer must have a solid grounding in JavaScript, with several years of experience using the older programming language. You should also search for someone who is capable of building complex applications, usually with TypeScript itself. Ask for evidence of experience successfully completing these types of projects.

Given TypeScript’s overwhelming popularity, you are unlikely to have a difficult time finding an experienced, qualified developer specializing in the language. And because it’s essentially JavaScript, an engineer who knows the parent language will be able to pick it up quickly. That’s not to say a JavaScript developer automatically knows how to code with TypeScript, but it does help considerably.

Still, since so many developers are eager to learn TypeScript, it’s a win-win.

Why should you use TypeScript?

The main reason to use TypeScript is to build complex or large applications that JavaScript can’t support. The language has a number of advantages, such as optional static typing, compilation — helping you easily spot errors in your code — excellent documentation, cross-platform capabilities, and simple debugging.

The language is also open-source, and you can use all the tools that assist JavaScript developers, including extensive libraries and frameworks.

How is TypeScript code compiled into JavaScript code?

In a nutshell, developers can use the TypeScript compiler to translate the code into usable, clean JavaScript code.

When should you not use TypeScript?

While it does come with a number of benefits, TypeScript isn’t ideal for simpler projects. It also takes a long time to compile the code to JavaScript, so it’s not the best choice for small-scale projects that require a quick turnaround. You should use JavaScript in these instances instead of TypeScript.

Explain the differences between JavaScript and TypeScript

TypeScript is built on and compiles to JavaScript. The main additions are static typing, more syntax and type support options in general, and compiler capabilities. While TypeScript isn’t necessarily superior to JavaScript for every project, it does lend a better development and user experience to particularly large and complex projects.

When and why should you use TypeScript over JavaScript?

The main purpose behind TypeScript is to facilitate projects JavaScript can’t handle. When your project grows in size — beyond JS’s limitations — or becomes increasingly complex, it’s a good idea to turn to TypeScript and then compile the code. JavaScript, after all, wasn’t built with these types of projects in mind. With the newer alternative, you’ll have an easier time catching mistakes. You’ll also end up with more modern, robust features.

What are the components of TypeScript?

Because TypeScript is more than just a language, it has several components. There is, of course, the language itself, including the keywords. There’s also the compiler, which translates the instructions and code into its JavaScript counterparts. The final piece is the Language Service, which essentially provides editing services to the developer.

Below is a sample job description for a TypeScript developer. Customize it based on your business’s unique needs and requirements.

We are looking for a TypeScript developer who is well-versed in additional programming languages to build large-scale applications, scale current products, and optimize the user experience. In this senior-level role, you’ll also oversee junior team members.

Responsibilities

Lead a small development team
Focus on backend development
Leverage TypeScript, JavaScript, and other programming languages to build large-scale apps
Research client and stakeholder requirements
Write clean code
Debug code
Create and deploy unit tests
Research best practices to focus on and optimize the user experience
Collaborate with QA specialists, designers, and other team members
Scale existing apps as needed
Research and implement means of improving the development process

Skills

At least 2 years of experience using TypeScript
At least 7 years of experience using JavaScript
Knowledge of HTML/CSS
Experience with CI/CD
Knowledge of Angular, Node, React, Jenkins, Git, and Knockout
Knowledge of SASS
Strong problem-solving, collaboration, interpersonal, and written and verbal communication skills
Experience with Ajax
Experience with functional programming
Bachelor’s degree in computer science or a related field (equivalent experience reviewed on a case-by-case basis)

TypeScript Modules

One of the ways TypeScript simplifies JavaScript is with the help of modules. TypeScript modules are designed to better organize code and are divided into 2 categories:

Internal Modules - used to logically group classes, interfaces, and functions into a single unit.
External Modules - specifies load dependencies between multiple external JavaScript files.

Conclusion

In the end, one of the most important questions is, “What can you use TypeScript for?” The answer is simple: If you can build it with JavaScript, you can build it with TypeScript, only bigger, more performant, and more easily. Because of this, TypeScript is ideal for larger companies that need JavaScript functionality at scale.

With TypeScript, you can build JavaScript applications for both client and server-side execution. And because TypeScript helps developers spot bugs as they type code, it’s a much more efficient language than JavaScript.

If this sounds like the perfect language to add to your current development team, you can test it out online or via the Python package manager, npm.