# MQTT array, display only 1 value **URL:** \ **Category:** Maker\ **Tags:** perspective\ **Created:** [January 13, 2024, 1:33pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240 "2024-01-13T13:33:09Z")\ **Posts on this page:** 19\ **Page:** 1
**Author:** ![Vidar\_Hetlelid](https://avatars.discourse-cdn.com/v4/letter/v/dfb087/32.png) [@Vidar\_Hetlelid](https://forum.inductiveautomation.com/u/Vidar_Hetlelid)\ **Post date:** [January 13, 2024, 1:33pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/1 "2024-01-13T13:33:09Z")
Hi there, Using MQTT Engine, im receiving an array of string, which I want to display only one of the string from the array. Im trying to index the array by using "[2]", but it displays all the strings in the array anyway. How can i display only ie. number 2? The MQTT variable: ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/b/7/b77f8e56e60762b703d25ef1013bc50ec030daad.png) Indexing and displaying the array, still gives all values. ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/6/e/6e8580bb243e5b82cc9085593f32b498df790033.png) Any ideas? 🙂 ---
**Author:** ![justinedwards.jle](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/justinedwards.jle/32/37854_2.png) [@justinedwards.jle](https://forum.inductiveautomation.com/u/justinedwards.jle)\ **Post date:** [January 13, 2024, 1:43pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/2 "2024-01-13T13:43:35Z")
Have you tried using a script transform on the value? Perhaps something like `list(value)[1]` would work. ---
**Author:** ![Transistor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/transistor/32/3380_2.png) [@Transistor](https://forum.inductiveautomation.com/u/Transistor)\ **Post date:** [January 13, 2024, 1:44pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/3 "2024-01-13T13:44:19Z")
It's probably nothing to do with the problem but you've shown the **Hops names** variable content but your binding is for **Hops use**. I've created a string array memory tag and can access each element as you are without difficulty. Can you show us the contents of Hops use? ---
**Author:** ![Vidar\_Hetlelid](https://avatars.discourse-cdn.com/v4/letter/v/dfb087/32.png) [@Vidar\_Hetlelid](https://forum.inductiveautomation.com/u/Vidar_Hetlelid)\ **Post date:** [January 13, 2024, 3:40pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/4 "2024-01-13T15:40:47Z")
Hi, your right i missed that. But the problem is the same for both, and also more variables. ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/f/f/ff16c643e5140d61a3aa1a35671a03ca2a9a5e81.png) ---
**Author:** ![Vidar\_Hetlelid](https://avatars.discourse-cdn.com/v4/letter/v/dfb087/32.png) [@Vidar\_Hetlelid](https://forum.inductiveautomation.com/u/Vidar_Hetlelid)\ **Post date:** [January 13, 2024, 3:43pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/5 "2024-01-13T15:43:42Z")
Well, i'm no good with the scripting part... How should I do this? 🙂 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/e/0/e0f31e5abefef7a3255f6f34c96f2d5fdd9ee4f3.png) ---
**Author:** ![Transistor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/transistor/32/3380_2.png) [@Transistor](https://forum.inductiveautomation.com/u/Transistor)\ **Post date:** [January 13, 2024, 3:47pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/6 "2024-01-13T15:47:00Z")
You've created a Script Transform. Justin's given you an Expression Transform. Remove the `[1]` from your tag path. Delete the script transform. Create an expression transform. Paste his code straight in and that's it. Think of expressions as being like Excel functions. It's not a program script but rather one or more functions or operations on variables and it just returns one result (or result set). ---
**Author:** ![Vidar\_Hetlelid](https://avatars.discourse-cdn.com/v4/letter/v/dfb087/32.png) [@Vidar\_Hetlelid](https://forum.inductiveautomation.com/u/Vidar_Hetlelid)\ **Post date:** [January 13, 2024, 3:50pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/7 "2024-01-13T15:50:25Z")
Thank you 🙂 I get this error 😕 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/8/f/8f79a465eb84f6d9110015b70769a35230f46f4f.png) ---
**Author:** ![Transistor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/transistor/32/3380_2.png) [@Transistor](https://forum.inductiveautomation.com/u/Transistor)\ **Post date:** [January 13, 2024, 4:06pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/8 "2024-01-13T16:06:13Z")
Hover over the Error\_Configuration error to read what the problem is. ---
**Author:** ![Vidar\_Hetlelid](https://avatars.discourse-cdn.com/v4/letter/v/dfb087/32.png) [@Vidar\_Hetlelid](https://forum.inductiveautomation.com/u/Vidar_Hetlelid)\ **Post date:** [January 13, 2024, 4:09pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/9 "2024-01-13T16:09:01Z")
![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/9/9/99f9ebf681fa7d78cba6d7b0caff8ec47f47e63f.png) ---
**Author:** ![Transistor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/transistor/32/3380_2.png) [@Transistor](https://forum.inductiveautomation.com/u/Transistor)\ **Post date:** [January 13, 2024, 4:11pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/10 "2024-01-13T16:11:59Z")
Sorry, I'm having a bad day. `list()` is a script function, not an expression function. Your first attempt was right but Justin, I think, missed the `{ }` braces. Try modifying the script to, `list({value})[1]` `{value}` is what's passed into the transform from the previous operation. ---
**Author:** ![Vidar\_Hetlelid](https://avatars.discourse-cdn.com/v4/letter/v/dfb087/32.png) [@Vidar\_Hetlelid](https://forum.inductiveautomation.com/u/Vidar_Hetlelid)\ **Post date:** [January 13, 2024, 4:16pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/11 "2024-01-13T16:16:14Z")
Uhm, different error this time as you see, list function is unknows 😕 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/e/7/e705008c75f12c61f01334576dc5e65e75f88e2f.png) As script: ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/b/d/bd0d6bb752af5e5bfd7dc85ccaf871a64c266a96.png) ---
**Author:** ![Transistor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/transistor/32/3380_2.png) [@Transistor](https://forum.inductiveautomation.com/u/Transistor)\ **Post date:** [January 13, 2024, 4:16pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/12 "2024-01-13T16:16:59Z")
I modified my previous post. It may be better to wait on someone else to respond! ---
**Author:** ![Transistor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/transistor/32/3380_2.png) [@Transistor](https://forum.inductiveautomation.com/u/Transistor)\ **Post date:** [January 13, 2024, 4:22pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/13 "2024-01-13T16:22:05Z")
Question for anyone else reading the thread: Vidar's MQTT tags display in Tag Browser are displayed as an array / list like this: [![](https://us1.discourse-cdn.com/inductiveautomation/original/3X/f/f/ff16c643e5140d61a3aa1a35671a03ca2a9a5e81.png) ](https://us1.discourse-cdn.com/inductiveautomation/original/3X/f/f/ff16c643e5140d61a3aa1a35671a03ca2a9a5e81.png) When I created a string array for testing it shows up like this: ![String array](https://us1.discourse-cdn.com/inductiveautomation/original/3X/a/9/a9e46b52ac7cdaec50976dadba93d95aa61ef900.png) Can you explain why? ---
**Author:** ![Vidar\_Hetlelid](https://avatars.discourse-cdn.com/v4/letter/v/dfb087/32.png) [@Vidar\_Hetlelid](https://forum.inductiveautomation.com/u/Vidar_Hetlelid)\ **Post date:** [January 13, 2024, 4:26pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/14 "2024-01-13T16:26:27Z")
Thats strange... Any chance that this has something to do with MQTT to do? Im publishing data from Nodered/MQTT. The data from nodered looks like this (array): ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/7/a/7a0395966d6753eda51dae7711ef1d23637f13af.png) Then, it is sent via MQTT node. Not sure what is done with the data inside this node. Maybe its sent as 1 complete string, instead of array? ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/6/3/63b0f944a0ff9fc6897d0809610065ab349114ba.png) Or maybe not, when i subscribe to this topic it is displayed as array: ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/1/8/18fa4e4ea16c081a306fc8011dfa919ff10064c0.png) ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/5/d53543127e8838648e09dca6737ab45d1ec29861.png) ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [January 13, 2024, 4:52pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/15 "2024-01-13T16:52:52Z")
I would expect this expression transform to work: ```auto {value}[1] ``` ---
**Author:** ![michael.flagler](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/michael.flagler/32/26272_2.png) [@michael.flagler](https://forum.inductiveautomation.com/u/michael.flagler)\ **Post date:** [January 13, 2024, 5:12pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/16 "2024-01-13T17:12:38Z")
Check the data type on the actual tag you're getting. I suspect it's passing it as a JSON string and not an array. Edit: If this is the case, you'll need something like: ```auto jsonGet({value},'[1]') ``` ---
**Author:** ![Vidar\_Hetlelid](https://avatars.discourse-cdn.com/v4/letter/v/dfb087/32.png) [@Vidar\_Hetlelid](https://forum.inductiveautomation.com/u/Vidar_Hetlelid)\ **Post date:** [January 13, 2024, 5:55pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/17 "2024-01-13T17:55:09Z")
Thanks, not sure where to check which data type is recieved... ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/e/1/e188ed36df884248f3feba64e6eef4236301b7b6.png) No luck with the jsonGet either... 😕 EDIT: Actually, this worked! 🙂 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/b/b/bb9d6c554cf623431534d5fc055fd7c336b22b16.png) ---
**Author:** ![michael.flagler](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/michael.flagler/32/26272_2.png) [@michael.flagler](https://forum.inductiveautomation.com/u/michael.flagler)\ **Post date:** [January 13, 2024, 6:14pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/18 "2024-01-13T18:14:06Z")
Glad it worked for you. I just realized I should have left off the return (I was mixing up expressions with scripting there for a bit). I'll edit it so no one else gets confused by it either. Usually there's a 3rd column that shows what your datatype is that I'm not seeing in your screenshot. ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/6/f/6fb9807c4d56ac41aa8195cd78ceebb11883cbef.png) ---
**Author:** ![Vidar\_Hetlelid](https://avatars.discourse-cdn.com/v4/letter/v/dfb087/32.png) [@Vidar\_Hetlelid](https://forum.inductiveautomation.com/u/Vidar_Hetlelid)\ **Post date:** [January 13, 2024, 6:17pm UTC](https://forum.inductiveautomation.com/t/mqtt-array-display-only-1-value/84240/19 "2024-01-13T18:17:26Z")
Ah! Data type column wasn't active, but it says its a string ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/b/3/b3d7905eab12566956fc69a13c4d4e18780076aa.png)