obj_literal_inheritance.js

// Method 2: constructor returning an object literal with methods attached
function Rectangle2(w,h) {
    var width = w, height = h;
    return {
        getWidth: function() { return width; },
        getHeight: function() { return height; },
        setWidth: function(w) { width = w; },
        setHeight: function(h) { height = h; },
        area: function() { return width * height }
    };
}

function PositionedRectangle2(w,h,xIn,yIn) {
    var x = xIn, 
        y = yIn,
        rect = new Rectangle2(w,h),
        me = {
            getX: function() { return x; },
            setX: function(xIn) { this.x = xIn; },
            getY: function() { return y; },
            setY: function(yIn) { this.y = yIn; }
        };
    return mixin(rect, me);
}