Understanding "export default" in JavaScript

Modern JavaScript frameworks heavily rely on the concept of modules, and among them, "export default" is a crucial feature. To delve into its functionality, let's dissect a real-world example:

Consider the following code snippet in the file SafeString.js:

// Build out our basic SafeString type
function SafeString(string) {
  this.string = string;
}

SafeString.prototype.toString = function() {
  return ""   this.string;
};

// Unfamiliar Syntax:
export default SafeString;

Question: What does "export default" mean in this context?

Answer: "export default" is a part of the ES6 module system that allows the module to export a single default value. In this case, it makes the SafeString class available as the default export of this module.

Simplified Explanation:

When you export a value as default, you can import it in other modules without explicitly specifying the named export. Instead, you can import it simply like this:

// Example in another module
import SafeString from './SafeString.js' // Assuming you have an appropriate import statement
let mySafeString = new SafeString('Hello, world!');
console.log(mySafeString); // Output: Hello, world!

The SafeString class is imported as the default export, making it accessible without the need for braces in the import statement.

Additional Note:

The ES6 module system provides a way to organize code and define dependencies. The "export default" syntax allows you to specify a single default value for a module, making it convenient for importing in other modules.