How to instantiate a javascript class in another js file?

Question

Suppose if I define a class in file1.js

function Customer(){     this.name="Jhon";     this.getName=function(){         return this.name;     }; }; 

Now if I want to create a Customer object in file2.js

var customer=new Customer(); var name=customer.getName(); 

I am getting exception: Customer is undefined, not a constructor.

But when i create a customer object in file2.js and pass it to file1.js then its working .

file1.js      function Customer(){         this.name="Jhon";         this.getName=function(){             return this.name;         }     }     function customer(){         return new Customer();     }  file2.js      var customer=customer();     var name=customer.getName(); 

but i want to create a customer object in file1.js using new Customer(). How can i achieve that?

Answer 1

It depends on what environment you're running in. In a web browser you simply need to make sure that file1.js is loaded before file2.js:

<script src="file1.js"></script> <script src="file2.js"></script> 

In node.js, the recommended way is to make file1 a module then you can load it with the require function:

require('path/to/file1.js'); 

It's also possible to use node's module style in HTML using the require.js library.

Answer 2

// Create Customer class as follows: export default class Customer {    getName() {      return 'stackoverflow';    } }  // Import the class  // no need for .js extension in path cos it gets inferred automatically import Customer from './path/to/Customer';  // OR const Customer = require('./path/to/Customer')   // Use the class var customer = new Customer(); var name = customer.getName();