Convert ObjectID (Mongodb) to String in JavaScript

Question

I want to convert ObjectID (Mongodb) to String in JavaScript. When I get a Object form MongoDB. it like as a object has: timestamp, second, inc, machine. I can\'t convert to

Answer 1

Here is a working example of converting the ObjectId in to a string

> a=db.dfgfdgdfg.findOne()
{ "_id" : ObjectId("518cbb1389da79d3a25453f9"), "d" : 1 }
> a['_id']
ObjectId("518cbb1389da79d3a25453f9")
> a['_id'].toString // This line shows you what the prototype does
function () {
    return "ObjectId(" + tojson(this.str) + ")";
}
> a['_id'].str // Access the property directly
518cbb1389da79d3a25453f9
> a['_id'].toString()
ObjectId("518cbb1389da79d3a25453f9") // Shows the object syntax in string form
> ""+a['_id'] 
518cbb1389da79d3a25453f9 // Gives the hex string

Did try various other functions like toHexString() with no success.

Answer 2

Acturally, you can try this:

> a['_id']
ObjectId("518cbb1389da79d3a25453f9")
> a['_id'] + ''
"518cbb1389da79d3a25453f9"

ObjectId object + String will convert to String object.

Answer 3

Assuming the OP wants to get the hexadecimal string value of the ObjectId, using Mongo 2.2 or above, the valueOf() method returns the representation of the object as a hexadecimal string. This is also achieved with the str property.

The link on anubiskong's post gives all the details, the danger here is to use a technique which has changed from older versions e.g. toString().

Answer 4

You could use String

String(a['_id'])

Answer 5

Use this simple trick, your-object.$id

I am getting an array of mongo Ids, here is what I did.

jquery:

...
success: function (res) {
   console.log('without json res',res);
    //without json res {"success":true,"message":" Record updated.","content":[{"$id":"58f47254b06b24004338ffba"},{"$id":"58f47254b06b24004338ffbb"}],"dbResponse":"ok"}

var obj = $.parseJSON(res);

if(obj.content !==null){
    $.each(obj.content, function(i,v){
        console.log('Id==>', v.$id);
    });
}

...

Answer 6

If you're using Mongoose along with MongoDB, it has a built-in method for getting the string value of the ObjectID. I used it successfully to do an if statement that used === to compare strings.

From the documentation:

Mongoose assigns each of your schemas an id virtual getter by default which returns the document's _id field cast to a string, or in the case of ObjectIds, its hexString. If you don't want an id getter added to your schema, you may disable it by passing this option at schema construction time.