What are some common polyfills I should know about?

What are some common polyfills I should know about?

Common polyfills include those for Array.prototype.includes, Promise, and Object.assign. Would you like details on any specific one?

Can you explain how to use the Promise polyfill?

Sure! You can include a Promise polyfill by adding a script tag to your HTML that links to a library like 'es6-promise'. Then, you can use Promises in your code as you normally would.

What about the Array.prototype.includes polyfill?

For Array.prototype.includes, you can add a polyfill function that checks if an array includes a certain value. Would you like a code example?

Yes, please provide a code example for that.

Here's a simple polyfill for Array.prototype.includes:

if (!Array.prototype.includes) {
  Array.prototype.includes = function(value) {
    return this.indexOf(value) !== -1;
  };
}