TypeScript 2.x By Example

Understanding classes

Prior to ES 2015, JavaScript developers did not have any concept of classes; the best way they could replicate the behavior of classes was with functions. The function provides a mechanism to group together related properties and methods. The methods can be either added internally to the function, or using the prototype keyword. The following is an example of such a function:

function Name (firstName, lastName) {  this.firstName = firstName;  this.lastName = lastName;  this.fullName = function() {  return this.firstName + ' ' + this.lastName ;  };}

In this preceding example, we have the fullName method encapsulated inside the Name function. Another way of adding methods to functions is shown in the following code snippet ...