What is TypeScript?

TypeScript is a free and open-source programming language developed by Microsoft. It is a superset of JavaScript that adds optional static typing, classes, interfaces, and other features to JavaScript. TypeScript is designed to make large-scale JavaScript applications more manageable and maintainable.

Why use TypeScript?

TypeScript offers several benefits over regular JavaScript:

Type Safety: TypeScript adds static typing to JavaScript, which helps catch errors at compile time rather than runtime. This means that you can catch errors before you even run your code, making your code more robust and reliable.
Scalability: TypeScript is designed to make large-scale JavaScript applications more manageable. It offers features like classes and interfaces that make it easier to organize and maintain code as it grows.
Tooling: TypeScript is supported by a wide range of development tools and editors, which makes development faster and more efficient. TypeScript also offers better IDE integration than JavaScript, with features like code completion, navigation, and refactoring.

Example

Let’s take a look at a simple example of TypeScript in action. Consider the following JavaScript code:

function add(a, b) {
  return a + b;
}

console.log(add(2, 3));
console.log(add('2', '3'));

This code defines a function add that adds two numbers together. When we call the function with two numbers, it works as expected and returns the sum. However, when we call the function with two strings, it concatenates the strings instead of adding them, which may not be what we intended.

Now let’s convert this code to TypeScript:

function add(a: number, b: number): number {
  return a + b;
}

console.log(add(2, 3));
console.log(add('2', '3'));

In this code, we’ve added type annotations to the function parameters and return type. We’ve specified that a and b are both of type number, and that the function returns a value of type number.

When we try to call the function with two strings, TypeScript throws a compilation error, which tells us that we’re trying to add two strings instead of two numbers. This error helps us catch potential bugs early and write more reliable code.

Conclusion

TypeScript is a powerful language that offers several benefits over regular JavaScript. It’s designed to make large-scale JavaScript applications more manageable, reliable, and efficient. By adding static typing and other features to JavaScript, TypeScript helps catch errors early and make development faster and easier.