问题
I am running into a hangup while trying to leverage Object.defineProperty() on a base object. I want to inherit properties from that object, using Object.create(), and then define more properties in the derived object (which may be inherited from there). I should note that I am targetting this at node.js.
Here's an example:
var Base = {};
Object.defineProperty(Base, 'prop1', {
enumerable:true,
get:function(){ return 'prop1 value';}
});
Object.defineProperty(Base, 'prop2', {
enumerable:true,
value : 'prop 2 value'
});
Object.defineProperty(Base, 'create', {
value:function(){
return Object.create(Base);
}
});
console.log(Base);
var derived = Base.create();
Object.defineProperty(derived, 'prop3', {
enumerable:true,
value:'prop 3 value'
});
console.log(derived);
Which outputs the following:
{ prop1: [Getter], prop2: 'prop 2 value' }
{ prop3: 'prop 3 value' }
I thought that console.log() would enumerate the inherited properties, as well as the property prop3 that I defined on the derived object. It would seem that it does not look up the prototype hierarchy for properties defined in this way. Is that correct?
I looked at overriding the toString() method for my object, but it seems that console.log() does not call that.
- How can I get all properties logged without having to enumerate through them?
- Is this a valid way to implement inheritance?
EDIT:
- Is there another function in node.js' libraries that would do the job and log the inherited properties?
回答1:
Firebug does log the inherited properties:
while Chrome gives you a tree-view which includes the inherited properties:
回答2:
you can use console.dir() where available
console.dir(derived)
and it'll show the inherited properties of your object on the __proto__ object
Edit : doesnt seem to show up on node though
来源:https://stackoverflow.com/questions/13300863/why-does-console-log-not-show-inherited-properties-from-object-create