Object vs Class vs Function

Question

I was wondering - what\'s the difference between JavaScript objects, classes and functions? Am I right in thinking that classes and functions are types of objects?

A

Answer 1

A Class in JS:

function Animal(){  

    // Private property
    var alive=true;

    // Private method
    function fight(){ //... }   

    // Public method which can access private variables
    this.isAlive = function() { return alive; } 

    // Public property
    this.name = "Joe";
}

// Public method
Animal.prototype.play = function() { alert("Bow wow!"); }

// .. and so on

Now when you create it's object

var obj = new Animal();

You can expect anything of this object as you would from objects in other language. Just the efforts to achieve it, was a bit different. You should also be looking at inheritance in JS.

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Getting back too your question, I'll reword it as:

Class  : A representation of a set with common properties.
object : One from the set with the same properties.


var Class = function() {alert('bar');}; // A set of function which alert 'bar'
var object = new Class();               // One of the functions who alert's 'bar'.