javascript inheritance from multiple objects

Question

I\'m not very well aquainted with javascript inheritance, and I\'m trying to make one object inherit from another, and define its own methods:

function Foo()         


        

Answer 1

One solution would be:

function FooB() {}
var p = new Foo();
p.methodA = function(){...}
p.methodB = function(){...}
p.methodC = function(){...}
...

FooB.prototype = p;

Update: Regarding expanding with an existing object. You can always copy the existing properties of one object to another one:

FooB.prototype = new Foo();
var proto = {
     /*...*/
};

for(var prop in proto) {
    FooB.prototype[prop] = proto[prop];
}

As long as proto is a "plain" object (i.e. that does not inherit from another object) it is fine. Otherwise you might want to add if(proto.hasOwnProperty(prop)) to only add non-inherited properties.