title: Azure DevOps pipeline template - how to concatenate a parameter
body: <p>All afternoon I have been trying to get my head around concatenating a parameter in an ADO template. The parameter is a source path and in the template a next folder level needs to be added. I would like to achieve this with a &quot;simple&quot; concatenation.
  The simplified template takes the parameter and uses it to form the inputPath for a PowerShell script, like this:</p>
  <pre><code>parameters:
    sourcePath: ''
  
  steps:   
  - task: PowerShell@2
    inputs:
      filePath: 'PSRepo/Scripts/MyPsScript.ps1'
      arguments: '-inputPath ''$(sourcePath)/NextFolder''
  </code></pre>
  <p>I have tried various ways to achieve this concatenation:</p>
  <ul>
  <li>'$(sourcePath)/NextFolder'
  <ul>
  <li>see above</li>
  </ul>
  </li>
  <li>'$(variables.sourcePath)/NextFolder'
  <ul>
  <li>I know sourcePath is not a variable, but tried based on the fact that using a parameter in a task condition it apparently only works when referencing through variables</li>
  </ul>
  </li>
  <li>'${{ parameters.sourcePath }}/NextFolder'</li>
  </ul>
  <p>And some other variations, all to no avail.
  I also tried to introduce a <em>variables</em> section in the template, but that is not possible.</p>
  <p>I have searched the internet for examples/documentation, but no direct answers and other issues seemed to hint to some solution, but were not working.</p>
  <p>I will surely be very pleased if someone could help me out.</p>
  <p>Thanx in advance.</p>