I've been learning and using TypeScript for the past year for various projects, and I have been enjoying it. TypeScript provides a great developer experience, and I believe that it has increased my productivity. I don't have to manually check for errors every time a change gets made, and the inline documentation helps me ship faster. In this article, I will give you an overview of TypeScript, share some of its features, and help you get started.
Since this is a variable name and we haven't defined its type, this variable can have any value. It doesn't matter if it's a string, number, boolean, or object. Hence, the below code will execute without errors:
Using TypeScript, you can define the type string for the variable name, as below:
If you change its value to any other type, the compiler returns an error. Type safety saves a lot of debugging time and helps in keeping the code consistent.
Features of TypeScript
You receive an object when you call any Contentful API. This object response contains the necessary data that you need. Similar to the Contentful API, other APIs also send an object as a response.
Interfaces get used to ensure that the object contains the required data with the correct data type. This object can be a response or request body or parameters for a function.
An interface has the following syntax:
Using the above syntax, we can create an interface Profile with the properties name and social.
The above interface can be used as follow:
The above is a simple example of interfaces. There are various other functionalities that interfaces provide. You can set optional properties, extend interfaces to add new properties, and more. To learn more about interfaces, refer to the TypeScript documentation.
Another feature that I find useful is Literal Types. Though, by themselves, they're not so useful. But one can combine them into unions, which makes the Literal Types useful.
The following example demonstrates the syntax of Literal Types.
Here, the variable social has the type "twitter." However, this isn't useful on its own.
In the above function, the second parameter can only take values that have the type of either "Alice" or "Bob." This helps us in writing functions that only accept a certain set of known values. They can do much more with Literal Types. Read the official documentation to learn more.
How to use TypeScript?
Now that you have a basic understanding of what TypeScript is, in this section, you will learn how to use TypeScript.
You can install TypeScript globally using the following npm command. The global installation allows you to run the tsc command anywhere from your terminal.
npm install -g typescript
Once you have installed TypeScript, create an index.ts file and add the following code:
You'll observe that the compiler creates an index.js file with the compiled code.
To configure the compiler options, you can either pass them with the CLI command or create a tsconfig.json. You can learn more about the various configuration options on the TSConfig Reference documentation page.
If you want to use TypeScript in your next Contentful project, we released contentful.js v10 in Beta with enhanced TypeScript support. Check out the changelog and let us know what you think!
Advantages of using TypeScript
Static typing – TypeScript comes with optional static typing and a type inference system, which means that a variable, declared with no type may be inferred by TypeScript based on its value.
Object oriented programming – TypeScript supports object-oriented programming concepts like classes, inheritance, etc.
Code editor support – IDEs or code editors like VS Code support autocomplete for a TypeScript codebase. They also provide inline documentation and highlight the errors.
What's the best way to learn TypeScript?
The TypeScript Handbook is a great place to learn about TypeScript. It explains the concepts well and contains relevant examples. The handbook is also regularly updated with new features.
The Contentful community members have also created apps and tools that can help generate type declarations for your content types and sync TypeScript with your content model.
If you're looking for your next TypeScript project, why don't you create an app for your Contentful space with App Framework? The boilerplate is available in TypeScript, where you can learn or brush up your TypeScript knowledge. Happy type checking!