Namespaces in TypeScript

Namespaces in TypeScript help organize code into logical groups. They also avoid name conflicts by grouping related functions, classes, or variables under a single namespace. Think of them like folders that keep your code neat and structured.

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Creating a Namespace

You can create a namespace with the namespace keyword.

namespace Utilities {
  export function logMessage(message: string): void {
    console.log(`Log: ${message}`);
  }

  export const version = "1.0.0";
}

• export: Only items marked with export are available outside the namespace.

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Using a Namespace

To access things inside a namespace, you prefix them with the namespace name.

Utilities.logMessage("Hello from Utilities!"); // ✅ Works
console.log(Utilities.version); // ✅ Output: 1.0.0

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Nested Namespaces

You can nest namespaces to group related code even further.

namespace App {
  export namespace User {
    export function getUserInfo(id: number) {
      return `User ID: ${id}`;
    }
  }
}

console.log(App.User.getUserInfo(42)); // ✅ Output: User ID: 42

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When to Use Namespaces vs. Modules

• Use namespaces when your code is in the same project or file.
• Use ES Modules (import/export) for code that spans multiple files or needs to be shared with others.

In modern TypeScript, ES Modules are often preferred for better compatibility.

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Aliasing a Namespace

You can create shorter aliases for long namespaces to make your code cleaner.

namespace App.Utilities {
  export function printDate() {
    console.log(new Date());
  }
}

import Utils = App.Utilities;
Utils.printDate(); // ✅ Output: Current date and time

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Key Takeaways

• Organized Code: Namespaces group related code together.
• No Conflicts: They prevent name clashes between variables or functions.
• Exporting Matters: Use export to make items accessible outside the namespace.
• Prefer Modules: For larger projects, ES Modules are more suitable.

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💡 Conclusion

Namespaces in TypeScript help structure your code and keep things organized. They are great for internal projects, but when working with larger or multi-file setups, consider using ES Modules instead.

Happy coding with Typescript! 🎉

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