A class is an extensible template that is used to create objects with member variables to hold the state of the object and member functions that deal with the behavior of the object.

The current version of JavaScript supports only function-based and prototype-based inheritance to build reusable components. The next version of JavaScript ECMAScript 6 supports object-oriented programming by adding the syntactic sugar for prototype-based class definitions and inheritance. However, TypeScript enabled developers to write code using object-oriented programming techniques, and it compiles the code down to JavaScript, which is compatible with all browsers and platforms:

class Customer { 
    name: string; 
    constructor(name: string) { 
        this.name = name; 
    } 
    logCustomer() { 
        console.log('customer name is ' + this.name); 
    } 
}  
let customer = new Customer("Rajesh Gunasundaram"); 

This Customer class has three members: a name property, a constructor, and a logCustomer method. The last statement outside the Customer class creates an instance of the customer class using the new keyword.