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Ahmad Mukahal
Ahmad Mukahal

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JavaScript factory functions and Object.create()

Do you know JavaScript factory function and its issues, and why we use Object.create() method instead?

Hello 🖐,

Factory functions in JS are any function that return an object.

like this one:

function createPerson(firstName, lastName) {
    return {
        firstName: firstName,
        lastName: lastName,
        getFullName() {
            return firstName + ' ' + lastName;
        }
    }
}
const person1 = createPerson("Ahmad", "Mukahal");
const person1 = createPerson("john", "Deo");

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and so on...

With the factory function, you create any number of the person objects you want without duplicating code.

What if we have one thousand persons? It will store a thousand objects in the memory heap! and this is not an efficient way.

Example:
Each object will have a different address in the memory and every object will have the getFullName() method, Ooh no, I'm not DRY!!

This is why the Object.create() method comes into play.

The Object.create() method creates a new object using an existing object as the prototype of the new object:

const person = {
firstName : "John",
lastName: "Deo",
getFullName() {
            return firstName + ' ' + lastName;
        }
}
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// Make prototype chain:

const me = Object.create(person);
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so, now me object has all properties and methods in person object, and it can hold its own props and methods and override props and methods as you want like this:

console.log(me.firstName) // John
me.firstName = "Ahmad";
me.lastName = "Mukahal";
console.log(me.firstName) // Ahmad
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What efficient is that !!

Hopefully enjoyed reading.

Ahmad Mukahal 🌹

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