Azure devops pipeline, powershell split string, convert to json and assign to pipeline variable doesn't work

Question

I want to convert a pipeline variable - delimited string - to a json array and assign the json array to an other pipeline variable. See my code below, output stays empty. What am I missing here?

script:

steps:
  - task: PowerShell@2
    inputs:
      targetType: inline
      script: |
        $test = "LZ-UK;LZ-ES;LZ-NL"
        $json = $test.Split(";") | ConvertTo-Json -AsArray
        Write-Host "##vso[task.setvariable variable=JsonLZ]$json"
        Write-Host "Assigned the variable"
        Write-Host "New `r`n $($JsonLZ)"
  - script: |
       echo ${{ variables.JsonLZ }}

output:

Starting: PowerShell
==============================================================================
Task         : PowerShell
Description  : Run a PowerShell script on Linux, macOS, or Windows
Version      : 2.200.0
Author       : Microsoft Corporation
Help         : https://learn.microsoft.com/azure/devops/pipelines/tasks/utility/powershell
==============================================================================
Generating script.
========================== Starting Command Output ===========================
/usr/bin/pwsh -NoLogo -NoProfile -NonInteractive -Command . '/home/vsts/work/_temp/380b437f-74c4-4883-9d4a-7b4f3ac79266.ps1'
  "LZ-UK",
  "LZ-ES",
  "LZ-NL"
]
Assigned the variable
New 
 
Finishing: PowerShell

Answer 1

You're very close. There were a few minor issues that I spotted with your YAML/PowerShell:

1. You forgot the semicolon after the variable name in "##vso[task.setvariable variable=JsonLZ]$json", it should be: "##vso[task.setvariable variable=JsonLZ;]$json"
2. You should be using $(JsonLZ) instead of ${{ variables.JsonLZ }}. The former will be evaluated at runtime, the latter at compile-time. Here's a link to the MS Docs: Understand variable syntax

Give this a try to see a working example:

name: Stackoverflow-Example-Pipeline
trigger:
    - none
variables:
  JsonLZ: 'UNSET'
stages:
    - stage: StageA
      displayName: "Stage A"
      jobs:
        - job: example_job
          displayName: "Example Job"
          pool:
            vmImage: "ubuntu-latest"
          steps:
          - task: PowerShell@2
            inputs:
              targetType: inline
              script: |
                  $test = "LZ-UK;LZ-ES;LZ-NL"
                  $json = $test.Split(";") | ConvertTo-Json -Compress
                  Write-Host "##vso[task.setvariable variable=JsonLZ;]$json"
                  Write-Host "Assigned the variable"
          - script: |
              echo $(JsonLZ)
              echo ${{ variables.JsonLZ }}