Example of Javascript Duck Typing?

Question

Some programmers advise against using pseudo classical inheritance in Javascript, but advise using duck-typing and giving each object a set of capabilities.

Is there

Answer 1

So you have these two functions:

function make ( props ) {
    var obj = Object.create( {} );
    Object.keys( props ).forEach(function ( key ) {
        obj[ key ] = props[ key ];
    });
    return obj;
};

function addMethods ( obj, methods ) {
    var proto = Object.getPrototypeOf( obj );
    Object.keys( methods ).forEach(function ( key ) {
        proto[ key ] = methods[ key ];
    });        
}

Usage:

var simba = make({
    name: "Simba",
    type: "lion"
});

addMethods( simba, {
    swim: function () {},
    run: function () {}
});

addMethods( simba, {
    hunt: function () {},
    kill: function () {}
});

Live demo: http://jsfiddle.net/UETVc/