title: Detect formula errors in Google Sheets using Script
body: <p>My ultimate goal is <a href="https://stackoverflow.com/questions/46574803/google-sheets-script-to-fix-predictable-error">here</a>, but because I've gotten no replies, I'm starting to learn things from scratch (probably for the best anyway). Basically, I want a script that will identify errors and fix them</p>
  
  <p>Well, the first part of that is being able to ID the errors. Is there a way using Google Script to identify if a cell has an error in it, and return a particular message as a result? Or do I just have to do an if/else that says "if the cell value is '#N/A', do this", plus "if the cell value is '#ERROR', do this", continuing for various errors?. Basically I want ISERROR(), but in the script</p>