在Javascript对象数组中，如果该元素本身是一个对象数组，如何通过名称/ ID来定位特定的数组元素？

Question

If I push objects created on the fly, including another internal array of objects, to an array, how can I add objects only to a specific object's array. Using Reviews for example:

reviews.push({ 'reviewer' : 'John', 
               'review' : 'This movie was the greatest', 
               'comments' : { 'commenter' : 'Dave',
                              'comment' : 'The review by John was too short'} 
             });

'comments' being the internal array of objects.

If at a later stage I want to add objects only to a specific object's 'comments' by it's parents name/ID, is it possible? And if so how would I go about doing it?

Using the example, If there is only 1 review with multiple comments, and the comments come at a later stage, how can I add new comments to the 'comments' array within the review object?

I am guessing I would need to have a review ID to stop duplicates etc, but that aside I'm not even sure syntactically how to do it or if it's even possible.

Thanks in advance.

Answer 1

First off, comments should be an array and you have an object.

Then proceed like this:

reviews[someIndex].comments.push( { commenter: 'john', comment: 'hello!!'});

Ie

if you need to add a comment to the first post do:

reviews[0].comments.push( { /* your comment */ } );

EDIT : I always used get() to retrieve an index but I seem to not be able to find much documentation about it, so I'm assuming (though I'm not sure) that [i] is a more standard way of doing things, hence why I changed the example. However the concept of pushing into comments doesn't change.

EDIT 2 : OP wants to target a particular element in an array. I would use Array.prototype.indexOf as described here where you can find a solution for browsers that do not support indexOf as well.

Answer 2

If you want to keep track of the reviews and comments by id's I'd do something like:

var reviews = {};
review_id = "#1234";
reviews[review_id] = {
    "reviewer": "John",
    "review": "This movie was the bestest",
    "comments": {
        "#456": {
            "commenter": "HAL 9000",
            "comment": "I'm afraid I can't let you do that Dave"
        }
    }
};

Adding a comment:

reviews[review_id].comments[comment_id] = { /* .. */ };

Answer 3

for(var i=0;i<reviews.length;i++){
if(reviews[i]["reviewer"]=="John"){
   var count=Object.keys(reviews[i].comments).length/2;
   reviews[i].comments["commenter"+(count+1)]="another commenter";
   reviews[i].comments["comment"+(count+1)]="some other comment";
   console.log(count);
}
}

output

commenter "Dave"

comment "The review by John was too short"

commenter2 "another commenter"

comment2 "some other comment"

http://jsfiddle.net/gkxcj/