在javascript中引用父对象

Question

I'm new to javascript and struggling with a problem below.

Let's think about this situation.

First, there is an object like this.

var bar = {
            'name' : 'bob',
            'comments' : []
          }

However because of some reasons, we have only one variable that named 'foo' and this is exactly same with bar.comments .

Second, because we need to reference the object bar , there must exist method in foo , named callParent . If we satisfy all these condition, we can get object bar using foo.callParent() .

To implement like above, first of all, I define a constructor name Custom .

function Custom(param){
    this.callParent = function(){
        console.log(param);
    }
}

and then, to use instance of Custom like array, inherit Array.

Custom.prototype = Array.prototype;

after that, I want to define object bar as like below.

var bar = {
            'name':'bob',
            'comments':new Custom(this)
          }

In that implementation, because I thought this means bar itself, I expected the result foo.callParent() will be bar but it was window . I think it's because in the context of calling foo.callParent() , this no longer means bar .

Finally, I solve this problem like this.

var bar = {
            'name':'bob',
            'comments':undefined,
            'init':function(){
                        this.comments = new Custom(this);
                        return this;
            }
}.init();

: Is there any way to solve this situation without help of other method like bar.init ? I want to solve this only with changes of constructor Custom ! Is it related with ?

Answer 1

Try this:

var bar = {
        'name':'bob'
      };
bar.comments = new Custom(bar);