# Bug or what is wrong?

**URL:** <https://discourse.nodered.org/t/bug-or-what-is-wrong/53595>\
**Category:** General\
**Created:** [11 November 2021 20:21 UTC](https://discourse.nodered.org/t/bug-or-what-is-wrong/53595 "2021-11-11T20:21:58Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![alfredolo](https://avatars.discourse-cdn.com/v4/letter/a/7c8e57/32.png) [@alfredolo](https://discourse.nodered.org/u/alfredolo)\
**Post date:** [11 November 2021 20:21 UTC](https://discourse.nodered.org/t/bug-or-what-is-wrong/53595/1 "2021-11-11T20:21:58Z")

</div>

Hello, i start become crazy.  
I have maked a big script in node red using the function node, now i deleted all just to understand what is wrong.  
Please help.

Just a timestamp and a function node with this code .  
I read 3 objects from flow or global (there is no difference), i write only the first object and all 3 get the same value.

Here is the output.

 ![node](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/1/4/14d7324f8429d18a30784ff5ed91a1befb5fdabc.jpeg)

What is wrong ?  
thank you

```auto
var tmp = {};

flow.set("simpos20",tmp);
flow.set("simpos50",tmp);
flow.set("simpos90",tmp);

var simpos20 = flow.get("simpos20");
var simpos50 = flow.get("simpos50");
var simpos90 = flow.get("simpos90");

node.warn(simpos20);
node.warn(simpos50);
node.warn(simpos90);

simpos20[1] = {"text":"hello"};

node.warn(simpos20);
node.warn(simpos50);
node.warn(simpos90);

return msg;

```

```auto
[
    {
        "id": "03084b6a8123d65d",
        "type": "function",
        "z": "4895129379e58dc6",
        "name": "",
        "func": "var tmp = {};\n\nflow.set(\"simpos20\",tmp);\nflow.set(\"simpos50\",tmp);\nflow.set(\"simpos90\",tmp);\n\nvar simpos20 = flow.get(\"simpos20\");\nvar simpos50 = flow.get(\"simpos50\");\nvar simpos90 = flow.get(\"simpos90\");\n\nnode.warn(simpos20);\nnode.warn(simpos50);\nnode.warn(simpos90);\n\n\nsimpos20[1] = {\"text\":\"hello\"};\n\nnode.warn(simpos20);\nnode.warn(simpos50);\nnode.warn(simpos90);\n\n\nreturn msg;\n",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 380,
        "y": 240,
        "wires": [
            []
        ]
    },
    {
        "id": "eaafbd92ddb9c638",
        "type": "inject",
        "z": "4895129379e58dc6",
        "name": "",
        "props": [
            {
                "p": "payload"
            },
            {
                "p": "topic",
                "vt": "str"
            }
        ],
        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "x": 210,
        "y": 240,
        "wires": [
            [
                "03084b6a8123d65d"
            ]
        ]
    }
]

```

---

<div class="post-metadata">

**Author:** ![knolleary](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/knolleary/32/3_2.png) [@knolleary](https://discourse.nodered.org/u/knolleary)\
**Post date:** [11 November 2021 20:26 UTC](https://discourse.nodered.org/t/bug-or-what-is-wrong/53595/2 "2021-11-11T20:26:13Z")

</div>

> [@alfredolo](#):
>
> ```auto
> flow.set("simpos20",tmp);
> flow.set("simpos50",tmp);
> flow.set("simpos90",tmp);
> 
> ```

You are setting all three context values to the same object - `tmp`. So when you update that one object, all three references to it see the change.

It would be better to initialise them as different objects:

```auto
flow.set("simpos20",{});
flow.set("simpos50",{});
flow.set("simpos90",{});

```

---

<div class="post-metadata">

**Author:** ![alfredolo](https://avatars.discourse-cdn.com/v4/letter/a/7c8e57/32.png) [@alfredolo](https://discourse.nodered.org/u/alfredolo)\
**Post date:** [11 November 2021 20:37 UTC](https://discourse.nodered.org/t/bug-or-what-is-wrong/53595/3 "2021-11-11T20:37:45Z")

</div>

Wow thank you.  
I was sure to get 3 new objects when use flow.get . So i get 3 pointer of the object ?

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [11 November 2021 20:38 UTC](https://discourse.nodered.org/t/bug-or-what-is-wrong/53595/4 "2021-11-11T20:38:16Z")

</div>

To clarify that a bit, javascript handles objects by reference. So `tmp` exists as an actual object in memory, but when you say something like  
`let x = tmp`  
or  
`flow.set("simpos20",tmp)`  
you are effectively setting x to be a pointer to the object, and setting the context contents to be a pointer to the object. If you then change the contents of `tmp` the variable x and the context variables are pointing the now changed object, so they all appear to change.

---

<div class="post-metadata">

**Author:** ![alfredolo](https://avatars.discourse-cdn.com/v4/letter/a/7c8e57/32.png) [@alfredolo](https://discourse.nodered.org/u/alfredolo)\
**Post date:** [11 November 2021 20:48 UTC](https://discourse.nodered.org/t/bug-or-what-is-wrong/53595/5 "2021-11-11T20:48:58Z")

</div>

Thank you very much !!!

---

<div class="post-metadata">

**Author:** ![UnborN](https://avatars.discourse-cdn.com/v4/letter/u/4491bb/32.png) [@UnborN](https://discourse.nodered.org/u/UnborN)\
**Post date:** [11 November 2021 21:14 UTC](https://discourse.nodered.org/t/bug-or-what-is-wrong/53595/6 "2021-11-11T21:14:43Z")

</div>

Node red provides a utility function that can clone the msg/object and 'unlink' it from being assigned by reference.

`RED.util.cloneMessage(tmp);`

**Test Flow:**

```auto
[{"id":"03084b6a8123d65d","type":"function","z":"5847b7aa62131d37","name":"","func":"var tmp = {};\n\nflow.set(\"simpos20\",RED.util.cloneMessage(tmp));\nflow.set(\"simpos50\",RED.util.cloneMessage(tmp));\nflow.set(\"simpos90\",RED.util.cloneMessage(tmp));\n\nvar simpos20 = flow.get(\"simpos20\");\nvar simpos50 = flow.get(\"simpos50\");\nvar simpos90 = flow.get(\"simpos90\");\n\nnode.warn(simpos20);\nnode.warn(simpos50);\nnode.warn(simpos90);\n\n\nsimpos20[1] = {\"text\":\"hello\"};\n\nnode.warn(simpos20);\nnode.warn(simpos50);\nnode.warn(simpos90);\n\n\nreturn msg;\n","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":640,"y":1580,"wires":[[]]},{"id":"eaafbd92ddb9c638","type":"inject","z":"5847b7aa62131d37","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":470,"y":1580,"wires":[["03084b6a8123d65d"]]}]

```

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [10 January 2022 21:15 UTC](https://discourse.nodered.org/t/bug-or-what-is-wrong/53595/7 "2022-01-10T21:15:29Z")

</div>

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