# How to set a global var with dynamic index on change node
**URL:** https://discourse.nodered.org/t/how-to-set-a-global-var-with-dynamic-index-on-change-node/66627
**Category:** General
**Created:** [18 August 2022 22:55 UTC](https://discourse.nodered.org/t/how-to-set-a-global-var-with-dynamic-index-on-change-node/66627 "2022-08-18T22:55:35Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@VMarques](https://discourse.nodered.org/u/VMarques)
#### Post date: [18 August 2022 22:55 UTC](https://discourse.nodered.org/t/how-to-set-a-global-var-with-dynamic-index-on-change-node/66627/1 "2022-08-18T22:55:35Z")
Hi There guys,
I am trying to,
- read a file containing a json string (all fine here),
- parse the keys and declare global vars with the name from the json,
The flow looks like this,
Split node loads the var name in msg.index
Here is my problem, I can't get the value of msg.index, tried moustache, @$, eval(), and some others, the variable is always declared with the literal content of the edit,
In short, how to read the a var content in a edit box - on the change node,
Thanks for any help,
---
### Author:  [@E1cid](https://discourse.nodered.org/u/E1cid)
#### Post date: [18 August 2022 23:24 UTC](https://discourse.nodered.org/t/how-to-set-a-global-var-with-dynamic-index-on-change-node/66627/2 "2022-08-18T23:24:15Z")
you could use [] notation, but it only works on a named property of the context in the change node (node-red \> 1.3).
e.g
`global.`foo[msg.index] would work
but
`global.`[msg.index] does not.
you can do
`global.set(msg.index, msd.payload);`
in a function node, if you can not work with an extra depth to your global vars.
---
### Author:  [@Andrei](https://discourse.nodered.org/u/Andrei)
#### Post date: [18 August 2022 23:32 UTC](https://discourse.nodered.org/t/how-to-set-a-global-var-with-dynamic-index-on-change-node/66627/3 "2022-08-18T23:32:08Z")
In short, based on what @E1cid mentioned above. You can use a code like below inside a function node. You pass a json object inside `msg.payload` ang get as result a set of global variables created.
```auto
let pay = msg.payload;
for (let prop in pay) {
global.set(prop, pay[prop])
}
return msg;
```
For instance, this following json:
```auto
{
"aaa": 10,
"bbb": 20
}
```
will result in the following global variables:
---
### Author:  [@VMarques](https://discourse.nodered.org/u/VMarques)
#### Post date: [20 August 2022 00:10 UTC](https://discourse.nodered.org/t/how-to-set-a-global-var-with-dynamic-index-on-change-node/66627/4 "2022-08-20T00:10:08Z")
Super, it works like a charm. Thanks you guys !
sharing a thought... it would be useful on the change node to allow dynamic var naming. The documentation discourages you to use coded interactions, unavoidable in this particular case.
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [3 September 2022 00:10 UTC](https://discourse.nodered.org/t/how-to-set-a-global-var-with-dynamic-index-on-change-node/66627/5 "2022-09-03T00:10:23Z")
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