dynamic-import.md

Dynamic import expressions are a new feature and part of ECMAScript that allows users to asynchronously request a module at any arbitrary point in your program.

This means that you can conditionally and lazily import other modules and libraries. For example, here’s an async function that only imports a utility library when it’s needed:

async function getZipFile(name, files) {
  const zipUtil = await import("./utils/create-zip-file");
  const zipContents = await zipUtil.getContentAsBlob(files);
  return new File(zipContents, name);
}

Use Cases for Dynamic Import

1. Code Splitting: You can split your code into smaller chunks that can be loaded on demand. This can significantly reduce the initial load time of your application.

2. Conditional Loading of Modules: You can conditionally load modules based on certain conditions. For example, you might load a polyfill only if it's needed, or load a module only if a certain feature is enabled.

3. Loading Modules on User Interaction: You can load modules when they're needed, such as when a user clicks a button or navigates to a certain part of your application.

button.addEventListener('click', async () => {
    const module = await import('./module.js');
    module.doSomething();
});

Pros and Cons

1. Performance: Dynamic imports can significantly improve the performance of your application by reducing the initial load time.

2. Efficiency: Dynamic imports allow you to load only the code that's needed, which can save bandwidth and memory.

Cons

1. Complexity: Dynamic imports can make your code more complex and harder to follow, especially if used excessively.

2. Error Handling: You need to handle errors that might occur when loading a module, such as network errors.

3. Browser Support: While dynamic imports are part of the ECMAScript specification, they might not be supported in all browsers or environments. You might need to use a polyfill or a module bundler that supports dynamic imports.