TypeScript is an open-source, object-oriented programming language that Microsoft made and keeps up to date. It is licensed under the Apache 2 license. Is that all there is to TypeScript though? And is it worth using?
In this article, we will talk about what TypeScript is, where it came from, and what it can do for you. Let’s not waste any time and just get started, shall we?
What is TypeScript?
Entering the programming environment, a person can hear the question: “What is TypeScript?” TypeScript is a programming language that is a further development of JavaScript and adds static typing to the projects. This feature helps the developers to detect the errors at the initial stages and that is why TypeScript is an effective tool for developing the large-scale applications.
Analyzing the current trends, it can be concluded that TypeScript has been gaining popularity more actively in recent years. Interestingly, the usage of TypeScript has increased by almost three folds from 12% in 2017 to 34% in 2022. This increase in usage comes at the same time as a slight decrease in the use of JavaScript, which may signal a change in the developer audience.
In this regard, TypeScript is beneficial because it is related to JavaScript, a widely used programming language. It complies with ECMAScript standards and supports the modern features of JavaScript. For instance, TypeScript 5.5, the newest one at the time of writing this in mid-2024, added inferred type predicates, control flow narrowing, and JSDoc @import among other things.
History
The journey of TypeScript started in 2010. The main leader of C# and the author of Delphi and Turbo Pascal Anders Hejlsberg was working at Microsoft. The language was created as a response to the lack of tooling and support for large scale applications built in JavaScript.
Microsoft invested two years of internal development to release TypeScript 0.8 in October 2012. However, there were some concerns at the beginning because this language did not have mature IDE support. However, there was value that TypeScript provided to this audience, which was a small but dedicated group of users who were willing to take the risk and develop with the language.
TypeScript slowly received more attention over time. The DefinitelyTyped project, which is a collection of high-quality TypeScript type definitions appeared. IDE and text editors added support for TypeScript such as Emacs, Vim, WebStorm, Atom, and Microsoft’s Visual Studio Code.
TypeScript 0.9, released in 2013, added support for generics. The language reached its 1.0 version at the Build developer conference in 2014. By July 2014, TypeScript had a new compiler, which was five times faster.
Fast forward to 2024, TypeScript is at version 5.5. It also remains relevant to JavaScript and proceeds with its mission to offer effective tools for working with JavaScript. Today, TypeScript is an example of how static typing works in a dynamically typed language.
Recommended reading: Best Javascript Tutorial for Beginners
Advantages
When we ask, “What is TypeScript?”, we uncover a language that has taken the development world by storm. TypeScript, a variant of JavaScript, offers a multitude of benefits that enhance code quality and boost developer productivity.
One of the key advantages of TypeScript is its support for static typing. This feature allows developers to catch many potential issues at build time, reducing the risk of runtime errors. For instance, if a function expects a Date object but receives a Number, TypeScript will flag this mismatch during the build process.
TypeScript also provides excellent tooling support. With integrated development environments (IDEs) like Visual Studio Code, developers can enjoy features like code completion and hinting. This not only improves productivity but also enhances the coding experience.
Adopting TypeScript doesn’t have to be an all-or-nothing decision. Its support for incremental adoption means that teams can start benefiting from static typing without having to convert their entire codebase to TypeScript. This flexibility makes TypeScript a practical choice for both new and existing projects.
Another advantage of TypeScript is its compatibility with newer ECMAScript features. This makes it suitable for both frontend and backend development in large-scale projects. Moreover, TypeScript is compatible with all JavaScript libraries and frameworks, allowing developers to leverage existing resources.
The popularity of TypeScript is evident in its growing usage statistics. According to the 2024 Developer Ecosystem Survey, JavaScript’s share has dipped slightly over the last three years, coinciding with a rise in TypeScript adoption. In fact, 20.7% of developers are expected to use TypeScript exclusively in 2023.
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How It Works
When we pose the question as “What is TypeScript?” we are getting into a language that builds on JS by incorporating static typing. TypeScript is a statically typed language that is a superset of JavaScript; this means that it has a type system that prevents errors before the JavaScript code is executed. This early error detection enhances development and the quality of the code since it is identified early enough.
TypeScript’s growth has been quite impressive. Its usage share rose from 12% in 2017 to 34% in 2022, tripling over the course of six years. This is because TypeScript integrates with any web browser, operating system, and environment that supports JavaScript.
Let’s illustrate TypeScript’s workings with a simple example:Let’s illustrate TypeScript’s workings with a simple example:
Here, greeting is a variable that has been defined with the type of string. TypeScript ensures that any value assigned to greeting is a string. If you attempt to assign a number to greeting, TypeScript will give an error.
There are not only simple variables in TypeScript; it has more to do with types. It can also define more sophisticated types, for example, interfaces and classes. For instance, consider this example:
In this code, User is an interface that characterizes an object with name and id attributes. UserAccount is a class that extends the User class which is an interface. TypeScript guarantees that any object of the UserAccount class complies with the structure prescribed by the User interface.
7 Features of TypeScript
TypeScript’s goal is to fill in these gaps so that application-scale development can be done more quickly and easily. It is a programming language that builds on JavaScript and has strong typing. But there is a lot more to it than that. Let’s take a look at some of the most important things about it.
1. Enhanced IDE Support
TypeScript makes programming with JavaScript a lot better overall for people who use it. This is mostly because TypeScript has made IDEs (integrated development environments) more useful. The TypeScript compiler sends rich type information to the IDE in real time. This gives the user a number of advantages that wouldn’t be possible otherwise.
First, mistakes are easier to find and fix. In the integrated development environment, compilation problems will show up as a straight red line while you are writing code (IDE). Code completion also lets you get help as you type if you have questions about the functions that a library might offer. This means that you don’t have to stop what you’re doing to look up more information online, which speeds up the process.
All of these changes to the IDE support help make users more productive overall.
2. Compilation
JavaScript is a programming language that is interpreted. So, it needs to be put into action so that we can be sure it is right. It means that you write all the codes in case something goes wrong, only to find that there is no output. Because of this, you will have to spend a lot of time looking through the code for mistakes. The TypeScript transpiler is in charge of making sure there are no mistakes. If it finds a syntax error, it will compile the code, which will result in compilation errors. Because of this, mistakes in the script will be easier to find.
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3. Static Typing & Type Inference
JavaScript is a programming language that is typed on the fly. To put it another way, JavaScript can’t figure out the type of a variable until the variable is set up during the runtime. In some cases, it may be too late to do this. Also, assuming wrongly that a variable is of a certain type could lead to serious bugs. TypeScript helps the weakly typed programming language JavaScript in this other way as well.
The language has an optional system for static typing and type inference that can figure out the type of variables that haven’t been declared. The TypeScript Language Service, which was already talked about, makes this system possible. Since TypeScript adds type support to JavaScript, it can cut down on the number of type errors that happen when JavaScript is compiled.
4. ECMAScript Features
Even though the ECMAScript standards have helped standardize the JavaScript programming language, not all web browsers and JavaScript runtime environments support all of the ECMAScript standards.
Here is where the language makes a difference by making it easier for users to use the future of JavaScript right now. Because of this, TypeScript lets developers use many of the newest ECMAScript features (like modules, lambda functions, classes, the spreader operator, and destructing) before web browsers or other environments support them fully.
Due to the flexibility of the language, users can also convert ECMAScript capabilities to earlier versions of ECMAScript targets that they choose. This makes it possible to try out new features without worrying about breaking compatibility with older browsers and JavaScript runtimes.
5. Type Definitions
Type definitions for already existent JavaScript libraries can be supported in TypeScript. The TypeScript Definition file (which has the extension.d.ts) offers definitions for JavaScript libraries that are hosted elsewhere. Therefore, programming written in this language may include these libraries.
6. Cross-Platform
Any platform that JavaScript is compatible with will also support TypeScript. Any operating system, including Windows, macOS, and Linux, is capable of hosting the TypeScript compiler thanks to its cross-platform nature.
7. Object-Oriented Language
TypeScript, unlike JavaScript, which hasn’t yet adopted object-oriented programming, lets you use object-oriented programming concepts like classes, interfaces, and inheritance. Object-oriented programming is not yet used in JavaScript.
On Learning TypeScript
This language has a lot of features, so it might be hard to learn and use them all at the same time. One thing you could do is learn TypeScript by converting existing JavaScript code base, one line at a time, to the TypeScript programming language. Because of this, moving to TypeScript could very easy.
The TypeScript Handbook is one of the best ways to learn about TypeScript. It does a good job of explaining the rules and gives examples that show how they work. The guide also gets updates on a regular basis that add new features. There are also tutorials that can help you change your JavaScript project to TypeScript or teach you how to use TypeScript to work with the DOM.
Should I Learn JavaScript First Instead?
When it comes to the question, “Should I learn JavaScript before TypeScript?” at Designveloper, our answer would be a definite yes. JavaScript is the base language on which TypeScript is derived from. It is as simple as starting with a crawl before moving on to a sprint.
JavaScript is the most used programming language globally. Many professionals use it. While the usage of JavaScript is still on the rise, TypeScript is gaining more popularity at a faster pace.
Why is this important? Well, TypeScript is actually a JavaScript that has more features added to it. This means that every proper JavaScript code is also a proper TypeScript code. TypeScript does not fix JavaScript, it just extends it with new features and tools that make it more solid and convenient for large projects.
For instance, let us consider type annotations which is a feature that TypeScript brings to the table. In JavaScript, you can write let message = ‘hello’, and later change it to message = 7 without any problems. But in TypeScript, if you declare let message: If you attempt to set string = ‘hello’ and then attempt to change it to message = 7, you will get an error. This is because TypeScript is more strict and eliminates a lot of errors that can be made in JavaScript.
We have been using JavaScript and TypeScript for several years at Designveloper. We have witnessed how TypeScript enhances the quality of code and the efficiency of the developers. But we also know that it is essential to have a solid base in JavaScript.
Switching from JavaScript to TypeScript
At Designveloper, we have also our own experience in migrating large projects from JavaScript to TypeScript. It is a very time-consuming process but the result is much more efficient and easily maintainable code.
The first challenge we face is to guarantee that all the participants in the transition are well acquainted with TypeScript. To overcome this, we ensure that we offer extensive documentation and training on TypeScript and all the features and syntax used.
The next issue is the management of the code base that is already in place. One cannot refactor a huge codebase overnight without experiencing some sort of problem. Our approach has been to write new modules in TypeScript and then gradually port over the old modules as they become due for update. In this manner, our quality control team only has to verify a few more aspects concerning the converted modules when testing new features.
Another distinction between the two is that TypeScript is much more strict when it comes to type checking. This implies that the type of all the variables must be declared correctly. This can be time consuming especially to the existing repositories. This is handled by declaring types for old code during conversion and actively looking for pre-defined type packages for third-party libraries.
From our case, it is evident that the advantages of migrating to TypeScript are much higher than the disadvantages. Static typing of TypeScript enables us to identify and correct mistakes before the implementation stage, which increases the reliability of the code. It also makes our code more readable and hence much easier to manage especially in large applications where codebase is a significant issue.
The Basics of Getting Started with TypeScript
As for Designveloper, we trust TypeScript. So, what is TypeScript? It is a statically typed programming language that is a superset of JavaScript and compiles to plain JavaScript. TypeScript adds static typing to JavaScript, which decreases the number of errors and improves developers’ work.
Getting started with TypeScript is very easy. First of all, you will have to install Node. js and npm. After installation, npm can be used to install TypeScript on your system globally. The command is as easy as npm install -g typescript.
When we go deeper into TypeScript we discover that it has features such as static typing, interfaces, and classes. These features make it a good choice for large projects since they ensure that the project is completed within the shortest time possible. In our experience at Designveloper, we have realized the benefits that TypeScript brings to the code and the developers.
Another advantage of TypeScript is its ability to compile to JavaScript. Any JavaScript program is also a TypeScript program, and TypeScript is a superset of JavaScript. This compatibility enables developers to gradually transition from using JavaScript to TypeScript on their projects, something we have done at Designveloper.
TypeScript also has good tooling support with IntelliSense that gives active hints as the code is typed. This feature has been very useful in our work at Designveloper since it allows identifying errors in the development phase.
The Downsides
As we have seen, TypeScript is a great tool, but like any other tool, it comes with its own set of issues. All these obstacles are real and we at Designveloper have gone through them.
Firstly, TypeScript is quite complex to learn especially for a person who has no prior experience with the language. It includes static types, interfaces, and generics, ideas not existing in JavaScript. This can prove to be time-consuming in the initial stages of development, hence, the process may take longer.
Secondly, TypeScript has the compilation step in which TypeScript code is converted to JavaScript while JavaScript does not have this step. This additional step can sometimes make the development process to take longer than it would have taken if the extra step was not included.
Thirdly, not all libraries and frameworks are supported by TypeScript to the full extent. While some of the popular ones like React and Vue do, some others may not. This lack of support can lead to problems when attempting to add TypeScript to the project.
Finally, there is a downside to using TypeScript, and that is that it can be overly rigorous at times. This strictness can cause some level of dissatisfaction since developers may have to spend more time on type annotations and making the code type-safe.
Still, at Designveloper, we think that the advantages of using TypeScript outweigh the mentioned drawbacks. This results in better code since it is able to detect errors at compile time rather than at run time as well as a more efficient development process. This has been evident in our own projects where the use of TypeScript has been of great benefit in minimizing on bugs and enhancing the quality of the code.
FURTHER READING: |
1. What Is ECMAScript and the 5 Latest ECMAScript Features |
2. Top 5 Javascript Frameworks That You Should Master |
3. 5 Best Javascript Books That You Can’t Avoid From Beginning |
Conclusion
TypeScript is basically JavaScript with support for types added to it. Because of this, we can’t learn TypeScript without first mastering JavaScript. Both have the same syntax and act the same way when they are run. This means that anything we learn about JavaScript will help us learn TypeScript at the same time.
In this article, we talked about what TypeScript is and how using it could help you in a number of ways. We looked at some of the things it can do and talked about how some of these things can make your life easier. Now is the time to add it to the project you are currently working on.
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