when to use this and not object literal in javascript?

Question

I was reading about OOP in JS, but confused between traditional OOP versus object literal. And I also found in github many great JS projects weren't written the 'OOP way'. They leverage the object leteral pattern like revealing pattern and singletons. I came from Java, now I'm consufed between below pattern, on when to use them.

OOP :

function cook(){
this.vege = 'something';
}

var Cook = new cook();
console.log(Cook.vege = 'something else')

Versus object literal way :

var cook = {

vege:"something"

}
cook.vege = "something else"

score 1 · Answer 1 · answered Jul 30 '16 at 02:45

Frequently, you'll only need an object literal. However, if you're wanting to create multiple object instances using the same patterns, you should use a constructor function to avoid repeating yourself. This is also important if you want to share things, like methods, across instances:

function Cook(name) {
  this.name = name;
  this.vege = 'something';
}

Cook.prototype = {
  cookSomething: function () { ... },
  doDishes: function () { ... }
};

Now you can do:

var fred = new Cook('Fred');
var lisa = new Cook('Lisa');

...and they'll all have a cookSomething and doDishes method.

score 0 · Answer 2 · answered Jul 30 '16 at 02:45

Let's say, there are 100 objects created for a particular student:

var Student = function (name) {
  this.name = name;
  this.greet = function () {
    console.log("My name is " + this.name);
  };
};

var praveen = new Student("Praveen Kumar");
var hello = new Student("Hello, World!");
var jeff = new Student("Jeff Atwood");

praveen.greet();
hello.greet();
jeff.greet();

But what if, suddenly I want to add another function like greet() function to:

console.log("Hola! This is " + this.name);

The now the "class" comes in handy.

var Student = function (name) {
  this.name = name;
  this.greet = function () {
    console.log("My name is " + this.name);
  };
};

var praveen = new Student("Praveen Kumar");
var hello = new Student("Hello, World!");
var jeff = new Student("Jeff Atwood");

Student.prototype.sayHola = function () {
  console.log("Hola! This is " + this.name);
};

praveen.sayHola();
hello.sayHola();
jeff.sayHola();

It is easy to add in one single prototype than keep adding for all the objects. This adds the function to all the objects.

when to use this and not object literal in javascript?

2 Answers2