Today we’re taking a look at What is TypeScript — an open-source, JavaScript-derived language that is both developed and maintained by Microsoft. Typescript is intended for the development of major, enterprise applications, and adds static type definitions to JavaScript.
What is TypeScript?
TypeScript was first deployed in October 2012 by Microsoft. Like Node.js, web application written in TypeScript can be deployed both client-side and server-side — it can be used to deliver server-side functionality with JavaScript. It’s supported in a number of IDEs, including Visual Studio Code, Webstorm, Vim, Emacs.
The primary advantage of TypeScript is that it provides static typing. The goal is to make it easier to create applications to scale with traditional JavaScript code; it’s easy for JavaScript programmers to transition directly to TypeScript. TypeScript code has to be compiled — and the TypeScript compiler itself is written in TypeScript.
TypeScript also provides for prototyping while JavaScript does not. On the other hand, JavaScript is far more lightweight and easier to deploy.
Thus, those who need the features of TypeScript can use TypeScript. But others may still find it more convenient to use JavaScript. And because TypeScript is written on JavaScript, many developers are able to move seamlessly between the two.
Component and Features of TypeScript
Because TypeScript is built on JavaScript, much of it is similar to what any other JavaScript programmer would need to know. But there are some extra components and features of TypeScript that make it more effective for larger, more robust applications.
- TypeScript can be used with other JS libraries, making TypeScript an easy way to extend already existing solutions or to integrate with other JavaScript products.
- JavaScript itself can be compiled within TypeScript. If you change the extension of a JS to a TS, the TypeScript compiler will compile it as though it is TypeScript.
- TypeScript is portable. It doesn’t require a virtual machine or anything else to run. It can be run throughout platforms just like JavaScript can be.
- TypeScript is compiled. JavaScript isn’t. Compiling TypeScript can make it easier to find errors before they become problems, whereas errors can exist in JavaScript and not be discovered.
- TypeScript has better typing. TypeScript has both static typing and a type interference system. The TLS system can infer typing based on the value of a variable if not declared.
- TypeScript has object-oriented programming. Interfaces, classes, and inheritance all make it easier to program large scale projects in TypeScript than in vanilla JavaScript.
The components of TypeScript are:
- The language. This is comprised of all the unique keywords, syntax, and type annotations within TypeScript that aren’t otherwise found in JavaScript.
- The compiler. This is the system that will compile JavaScript or TypeScript code into JavaScript, making it platform-agnostic and accessible.
- The service. This system provides editor operations such as code formatting, colorization, and signature help.
Other than this, learning TypeScript is really the process of learning JavaScript, and vice versa. TypeScript also has declaration files. which are essentially the same as header files in C/C++.
How to install TypeScript
Now that you know why TypeScript is used, how is TypeScript installed?
TypeScript can be installed in three ways:
- An NPM Module. TypeScript is a package within the NPM registry known as “typescript.” It can be installed by typing “npm install typescript –save-dev.” From there, the compiler can be run by typing “npx tsc.”
- A NuGet Package. Through the “Manage NuGet Packages” window, TypeScript can be installed. Otherwise, it can be installed through the “NuGet Package Manager Console.”
- A Visual Studio Extension. If the project cannot use NuGet, the TypeScript Visual Studio Extension can instead be installed.
Need to learn more? You can find out how to install TypeScript through a fast tutorial video. When connecting database access for TypeScript, you can use a toolkit like Prisma.
TypeScript Best Practices
#1 – Use “strict.” TypeScript doesn’t generally run with “strict” mode enabled. When you learn more about TypeScript, you can turn the “strict” mode off. However, as a beginner to the TypeScript parameters, it’s often easier to learn what does and doesn’t work by putting on “strict” mode.
#2 – Use opaque types
When creating code, it can be easy to use vague typing such as “strings,” which can essentially be anything. Opaque types give you more control over what is and isn’t considered to be acceptable within given parameters.
#3 – Get a code formatting system.
A code formatting system like “Prettier” can make code more attractive and manageable. This is especially true when developing large enterprise applications, as code may be written and maintained by different people with different styles.
#4 – Use Utility types.
Utility types can also be an excellent tool for ensuring that variables have the right types, even if those types might be fairly niched or (on the other side of the spectrum) too open.
#5- Don’t use custom TypeScript namespaces or modules.
Use standard JavaScript modules instead of the use of import and export.
Use import rather than “require.” Since ES6 modules are standard within TypeScript, “import” is used rather than “require.”
Conclusion
For organizations trying to create large, scalable solutions in JavaScript — both client-side and server-side — TypeScript can provide for an excellent extension.
TypeScript adds new functionality to JavaScript which makes it easier to manage large scale deployments. At the same time, TypeScript isn’t really necessary for smaller and lighter JavaScript applications. Many of its benefits (such as compiling code) are best used for larger projects.