title: Check if all files are available in storage - Azure ADF
body: <p>In Azure data factory, how to check if an array of string(filenames) contains value?</p>
  <p>I'm getting file names from get metadata activity and I need to check if all 4 filenames that I have are available in storage account before proceeding.</p>
  <p>I'm expecting 4 files into the storage account and I need to check if all the 4 files are available. I need to explicitly check against the file names and not the number of files - this being a requirement</p>
  <p>When I try to validate it using the child item from get meta data I am getting error <code>&quot;array elements can only be selected using an integer index.&quot;</code> The issue here is that the file could be present at any index in the next load</p>
  <p>Is there a better way to validate the filename?</p>
  <p>Appreciate your help, thanks in advance</p>