TypeScript is an open-source programming language developed and maintained by Microsoft. It is a typed superset of JavaScript, which means that all JavaScript code is valid TypeScript code, but TypeScript adds some additional features that make it easier to write and maintain large and complex codebases.
One of the main reasons why TypeScript is essential is that it allows developers to add type annotations to their code. This means they can specify the data type of variables, function arguments, and return values, which can help prevent many common bugs and make the code easier to read and understand.
Originally published on ByRayRay.dev.
Function without types
For example, consider the following JavaScript code:
function add(x, y) {
return x + y;
}
const result = add(1, "2");
In this code, the add function is supposed to add two numbers, but because JavaScript is a dynamically typed language, it will silently try to convert the string "2" to a number and then add it to 1, producing the wrong result. This can be very difficult to debug, especially in large and complex codebases.
Function with types
With TypeScript, we can add type annotations to the add function to specify that it takes two numbers as arguments and returns a number:
function add(x: number, y: number): number {
return x + y;
}
const result = add(1, "2"); // This will cause an error
Now, if we try to pass a string as the second argument to the add function, the TypeScript compiler will give us an error, alerting us to the fact that there is a bug in our code. This can save us a lot of time and frustration, and it can help ensure that our code is correct and free of bugs.
Another reason why TypeScript is important is that it provides many features that are not available in vanilla JavaScript. For example, TypeScript supports classes, interfaces, and modules, which can help us organize our code more logically and maintainable way. It also supports type inference, which can automatically infer the types of variables and expressions based on the context in which they are used. This can save us a lot of time and effort, and it can make our code more concise and readable.
Overall, TypeScript is a valuable tool for writing great and readable JavaScript code. It allows us to add type annotations to our code, which can help prevent bugs and make the code easier to understand. It also provides additional features unavailable in vanilla JavaScript, which can help us write more modular and maintainable code. If you are working on a large or complex JavaScript project, it is worth considering using TypeScript.
If you want to start learning TypeScript today? I wrote a great post "TypeScript for beginners" where I teach how you can use all the essential parts of TypeScript. As an example I use 🍕😅
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