necessity of prototype declaration in every method
<p>Is is necessary to have "prototype" appended to every method of class.. or namespace is enough in example below (for full example refer link below). I understand that it is good practice but do inheritance really require the keyword "prototype" declare in every method.. what is the real necessity inheritance</p>

<pre><code>if(animal === undefined) var animal  = {};

animal.Mammal.prototype.haveABaby=function(){ 
    var newBaby=new Mammal("Baby "+this.name);
    this.offspring.push(newBaby);
    return newBaby;
} 
animal.Mammal.prototype.toString=function(){ 
    return '[Mammal "'+this.name+'"]';
} 
</code></pre>

<p><a href="http://phrogz.net/JS/classes/OOPinJS2.html" rel="nofollow">http://phrogz.net/JS/classes/OOPinJS2.html</a></p>
