Generating objects using functions
We can generate objects using function but each time new object is created, there are multiple copies of same functions.
function personCreator(name, age) {
const newPerson = {};
newPerson.name = name;
newPerson.age = age;
newPerson.increaseAge = function() {
newPerson.age++;
};
return newPerson;
};
const ashish = personCreator("Ashish Patel", 24);
ashish.increaseAge()Generating objects using prototypes
So we use prototypes to create objects for storing functions with their associated data.
function PersonCreator(name, age){
this.name = name;
this.age = age;
}
PersonCreator.prototype.increaseAge = function(){
this.age++;
};
// Using new creates a new object and returns it
const ashish = new PersonCreator(“Ashish Patel”, 24)
ashish.increaseAge()Subclassing can be achieved by below code
function PersonCreator(name, age) {
this.name = name;
this.age = age;
}
PersonCreator.prototype.increaseAge = function(){
this.age++;
}
function PersonCreatorWithCaste(name, age, caste){
PersonCreator.call(this, name, age);
this.caste = caste;
}
PersonCreatorWithCaste.prototype = Object.create(PersonCreator.prototype);
PersonCreatorWithCaste.prototype.displayCaste = function(){
console.log(this.caste);
}
const ashish = new PersonCreatorWithCaste("Ashish Patel", 25, "Agharia");
console.log(ashish.age);
ashish.increaseAge();
console.log(ashish.age);
ashish.displayCaste();Generating objects using classes
Class was introduced with ES2015, it let us write the shared methods in one place instead of writing the constructor and shared methods separately.
class PersonCreator {
constructor (name, age){
this.name = name;
this.age = age;
}
increaseAge(){
this.age++;
}
}
const ashish = new PersonCreator("Ashish Patel", 24);
ashish.increaseAge();Subclassing in ES2015 can be achieved by below code
class PersonCreator {
constructor (name, age){
this.name = name;
this.age = age;
}
increaseAge(){
this.age++;
}
}
class PersonCreatorWithCaste extends PersonCreator {
constructor(name, age, caste){
super(name, age);
this.caste = caste;
}
displayCaste(){
console.log(this.caste);
}
}
const ashish = new PersonCreatorWithCaste("Ashish Patel", 24, "Agharia");
console.log(ashish.age);
ashish.increaseAge();
console.log(ashish.age);
ashish.displayCaste();