The Power Of Constructor Pattern In JavaScript: Unlocking The Full Potential


Vishnu Prasath

September 14, 2023

Last updated: November 15, 2023

Constructor Pattern In JavaScript

An Introduction To Constructor Pattern In JavaScript

As a matter of fact, JavaScript supports multiple design patterns for object creation that are designed to act as templates for other objects. And one such common pattern is the Constructor pattern. The Constructor Pattern is a design pattern in JavaScript that involves defining a constructor function which can be used to create objects with similar properties and methods. 

The constructor function acts as a blueprint or template for creating new objects of the same type. The Constructor design Pattern is widely used in JavaScript programming for creating custom data types, such as classes or modules, and for creating instances of third-party libraries or frameworks.

Having said that, let’s explore the inner workings of the Constructor Pattern in JavaScript. 

What Is Constructor Pattern In JavaScript?

The Constructor design pattern is a way of creating objects in JavaScript and is a special function that is used to create an instance of an object. It derives its name as a constructor function as it is used to construct or create an object with properties and methods. 

Here the properties are the values that are stored in an object, and methods are the functions that are attached to an object. Thus, when an object is created using the JavaScript Constructor pattern, it has its own properties and methods that are independent of other objects.

Creating Objects With The Constructor Pattern

To create an object using the Constructor pattern, you will first need to define a constructor function.

Here is an example of a constructor function that creates an object with two properties:

creating objects with two properties in constructor pattern

In this example, the constructor function creates a CalibraintEmployees object with two properties: firstName and lastName. The constructor function takes two parameters, firstName and lastName, which are used to set the values of the properties.

To create a new CalibraintEmployees object, you can use the new keyword followed by the name of the constructor function and the arguments:

creating a new object

In this example, we have created two CalibraintEmployees objects: employee1 and employee2. Each object has its own properties and methods, which are independent of each other.

Using Prototypes With The Constructor Pattern

The JavaScript Constructor Pattern can also be extended using prototypes. Prototypes are used to add properties & methods to an object after it has been created and can be shared among all objects created using the same constructor function. 

Here is an example of adding a method to the CalibraintEmployees object using a prototype:

adding a method to the object using a prototype

In this example, we have added a getFullName method to the CalibraintEmployees object using a prototype. The method appends the firstName and lastName of the CalibraintEmployees and returns.

To use the getFullName method, you can call it on a CalibraintEmployees object:

constructor pattern getFullName method

In this example, we have called the getFullName method on the employee1 object, which returns “Lokeshkanagaraj”. 

Advantages Of Constructor Pattern In JavaScript

As mentioned above, the constructor pattern in JavaScript is a design pattern used to create objects. Here are some practical applications of the constructor pattern:

Encapsulation: Constructors encapsulate object properties and methods, making it easier to manage and manipulate related data.

Inheritance: Constructors can be used to create parent and child objects, enabling the implementation of inheritance and prototype chains.

Modular Code: Constructors help organize your code by grouping related properties and methods into a single constructor function.

Custom Data Types: Create custom data types or classes using constructors, like defining a “Car” class with properties and methods for car objects.

Code Maintainability: Using constructors makes your code more readable and maintainable by clearly defining how objects are structured.

DOM Manipulation: Constructors can be used to represent and manipulate DOM elements in web application development.

Closing Lines: 

The constructor pattern in JavaScript provides a structured and efficient way to create objects with shared properties and methods. By using constructor functions, you can easily instantiate multiple instances of objects, ensuring code reusability and maintaining a clear separation between data and behavior. This pattern forms the foundation for object-oriented programming in JavaScript and remains a fundamental concept for building robust and organized code in the language.

Frequently Asked Questions On Constructor Patterns In JavaScript

1. What Is A Constructor Function In JavaScript?

A constructor function in JavaScript is a blueprint for creating objects. It defines the structure and behavior of objects of a particular type.

2. How Do You Create An Instance Of An Object Using A Constructor Function?

You can create an instance of an object using a constructor function by using the new keyword followed by the constructor function’s name. For example: ‘const myObject = new MyConstructor();’

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