# Increment String
**URL:** https://discourse.nodered.org/t/increment-string/25495
**Category:** General
**Created:** [25 April 2020 18:10 UTC](https://discourse.nodered.org/t/increment-string/25495 "2020-04-25T18:10:31Z")
**Posts on this page:** 13
**Page:** 1
### Author:  [@d0d04m3](https://discourse.nodered.org/u/d0d04m3)
#### Post date: [25 April 2020 18:10 UTC](https://discourse.nodered.org/t/increment-string/25495/1 "2020-04-25T18:10:31Z")
hi I need Increment String by one but I cant
sow I convert to number for incremented but nothing
and this
```auto
var id = Number(msg.payload[0]._id);
id++;
msg.payload[0].ack_id = (id).toString();
node.send(msg);
```
not work
any help
---
### Author:  [@JGKK](https://discourse.nodered.org/u/JGKK)
#### Post date: [25 April 2020 18:17 UTC](https://discourse.nodered.org/t/increment-string/25495/2 "2020-04-25T18:17:20Z")
This is because your id string contains letters and not just numbers. So the Number() method returns NaN not a number.
Johannes
Edit here is a link that explains this behavior of the Number() Method [https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global\_Objects/Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [25 April 2020 18:22 UTC](https://discourse.nodered.org/t/increment-string/25495/3 "2020-04-25T18:22:33Z")
If you are using it just to confirm receipt, why not simply return the \_id (i.e. why do you have to increment it?)
---
### Author:  [@d0d04m3](https://discourse.nodered.org/u/d0d04m3)
#### Post date: [25 April 2020 18:24 UTC](https://discourse.nodered.org/t/increment-string/25495/4 "2020-04-25T18:24:16Z")
oh yes am wrong I thought HEX valeu
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### Author:  [@d0d04m3](https://discourse.nodered.org/u/d0d04m3)
#### Post date: [25 April 2020 18:28 UTC](https://discourse.nodered.org/t/increment-string/25495/5 "2020-04-25T18:28:34Z")
> [@Steve-Mcl](#):
>
> If you are using it just to confirm receipt, why not simply return the \_id (i.e. why do you have to increment it?)
this NEXT Record from MongoDB
so I need find this id into database for check its present or not
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [25 April 2020 18:31 UTC](https://discourse.nodered.org/t/increment-string/25495/6 "2020-04-25T18:31:42Z")
Ok,so is that an automatic ID or does your systems generate it?
If it's automatically generated by mongo I'm not certain you can guarantee the next id will be hex+1
---
### Author:  [@d0d04m3](https://discourse.nodered.org/u/d0d04m3)
#### Post date: [25 April 2020 18:45 UTC](https://discourse.nodered.org/t/increment-string/25495/7 "2020-04-25T18:45:59Z")
this Auto ID generated by mongodb when store any thing
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [25 April 2020 19:04 UTC](https://discourse.nodered.org/t/increment-string/25495/8 "2020-04-25T19:04:33Z")
Then I'm struggling to understand the logic. Anyhow, assuming it's always alphanumerically greater then can't you select next record(s) where \_id I'd greater than \_id?
E.g...
```auto
db.products.find({_id: {$gt: ObjectId("4fdbaf608b446b0477000142" )}}).sort({_id:1}).limit(1);
```
---
### Author:  [@d0d04m3](https://discourse.nodered.org/u/d0d04m3)
#### Post date: [25 April 2020 20:18 UTC](https://discourse.nodered.org/t/increment-string/25495/9 "2020-04-25T20:18:02Z")
ok I am solved with add UUID node generator to any new incoming event and not ACK type of msg
before stored in dB
---
### Author:  [@d0d04m3](https://discourse.nodered.org/u/d0d04m3)
#### Post date: [25 April 2020 20:33 UTC](https://discourse.nodered.org/t/increment-string/25495/10 "2020-04-25T20:33:46Z")
> [@Steve-Mcl](#):
>
> Then I'm struggling to understand the logic. Anyhow, assuming it's always alphanumerically greater then can't you select next record(s) where \_id I'd greater than \_id?
>
> E.g...
yes its logic to work
---
### Author:  [@d0d04m3](https://discourse.nodered.org/u/d0d04m3)
#### Post date: [25 April 2020 20:43 UTC](https://discourse.nodered.org/t/increment-string/25495/11 "2020-04-25T20:43:59Z")
but I see this error
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### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [25 April 2020 23:31 UTC](https://discourse.nodered.org/t/increment-string/25495/12 "2020-04-25T23:31:26Z")
Actually, not sure how you'd do this ina function node.
Normally in a nodejs project `ObjectId` is imported
E.g. `var ObjectId = require('mongodb').ObjectID;`
Does the mongo nodes have a find node? Or a means of accessing ObjectId?
Sorry, I don't know how to help here.
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [9 May 2020 23:31 UTC](https://discourse.nodered.org/t/increment-string/25495/13 "2020-05-09T23:31:26Z")
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