BabelJS Polyfills

BabelJS Polyfills: Polyfills are code snippets that provide modern JavaScript features to older browsers that do not support them natively. Babel can automatically include polyfills for features that are not supported by the target environments.

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1. Using Babel Polyfills

To use Babel polyfills, you need to install the necessary package:

npm install @babel/polyfill

In your application entry point, import the polyfill at the top of your JavaScript code:

// Import Babel polyfills
import '@babel/polyfill';

This imports the Babel polyfill, which includes all necessary polyfills based on your Babel configuration.

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2. Customizing Babel Polyfills

You can also customize the polyfills included by Babel to only include the ones necessary for your target environments. Modify your .babelrc file to specify the targets:

{
  "presets": [
    ["@babel/preset-env", {
      "useBuiltIns": "usage",
      "corejs": 3,
      "targets": {
        "chrome": "58",
        "ie": "11"
      }
    }]
  ]
}

In this example, Babel will only include polyfills necessary for targeting Chrome 58 and Internet Explorer 11.

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3. Conclusion

BabelJS Polyfills enable developers to ensure compatibility with older browsers by providing modern JavaScript features. By using Babel with polyfills, developers can write code using the latest ECMAScript syntax while ensuring it runs smoothly across a wide range of browser environments.