flatMap, flat, flatten doesn"t exist on type any[]

🔍 Understanding the Problem: flatMap, flat, and flatten are missing on type any[]

So, you're using Chrome 70 and everything runs smoothly because Chrome adds these cool methods like .flatMap, .flatten, and .flat to arrays. But here's the catch: TypeScript doesn't recognize these methods and throws a warning at you saying, "Property 'flatMap' does not exist on type 'any[]'."

Why is this happening?

😕 Common Issues: Missing typings and outdated TypeScript version

The reason behind this warning is that there are no typings available for these methods in your Angular 6 project, which uses TypeScript ~2.9.2. The typings help TypeScript recognize the existence of these methods on arrays. Additionally, importing import 'core-js/es7/array'; in your polyfills.ts file didn't solve the problem either.

💡 Easy Solution: Adding the correct typings

To fix this issue, you need to install the correct typings for these methods.

1. Open your terminal.

2. Run the following command: npm install --save-dev @types/node.

3. Once the installation is complete, go to your .tsconfig file and add "es2019" or "es2021" to the lib field, depending on the version of TypeScript you're using.

For example:

"compilerOptions": {
   "lib": ["dom", "es2019"]
}

or

"compilerOptions": {
   "lib": ["dom", "es2021"]
}

1. Save the changes and restart your TypeScript server (if running).

🚀 Compelling Call-to-Action: Share your experience and help others!

Now that you've successfully solved the issue, it's time to share your experience with others and help them out too. Feel free to share this blog post with your friends, colleagues, or anyone facing the same problem. Let's spread the knowledge and make coding easier for everyone! 👩‍💻👨‍💻

📝 Wrapping Up:

In this blog post, we discussed the problem of missing methods, such as flatMap, flat, and flatten, on type any[]. We identified common issues, provided an easy solution, and encouraged you to share your knowledge with others. Remember to stay updated with typings and TypeScript versions to avoid such issues in the future.

Have you ever faced similar problems? How did you solve them? Let us know in the comments below! 🗣️✨