𝗝𝗮𝘃𝗮𝗦𝗰𝗿𝗶𝗽𝘁 𝗖𝗼𝗻𝘀𝘁𝗿𝘂𝗰𝘁𝗼𝗿 𝗙𝘂𝗻𝗰𝘁𝗶𝗼𝗻𝘀

Use constructor functions to create many objects with the same structure.

A constructor function acts as a blueprint. You use the new keyword to build objects from this blueprint. You should start constructor names with a capital letter.

How it works:

When you use the new keyword, JavaScript does four things:

The this keyword is essential. Inside the function, this refers to your new object.

Example:

function Employee(name, salary) { this.name = name; this.salary = salary; }

const emp1 = new Employee("Ram", 50000); const emp2 = new Employee("Kumar", 60000);

Both objects share the same structure.

Adding methods:

You can add functions inside a constructor.

function Employee(name, salary) { this.name = name; this.salary = salary; this.displayInfo = function() { console.log(this.name + " earns " + this.salary); }; }

Memory management:

Adding methods directly inside the constructor creates a new copy for every object. This uses more memory.

Instead, use the prototype property.

Employee.prototype.greet = function() { console.log("Hello " + this.name); };

Now, every employee shares one single copy of the greet method. This makes your code more efficient.

Summary:

Source: https://dev.to/dev_saravanan_journey/javascript-constructor-functions-k6k