Cannot read property 'getDataRange' of null [duplicate]

Question

Im very new working with google script and APIs and Im trying to run a piece of code that makes the sheet in to a Json however I`m facing an issue where it says:

    TypeError: Cannot read property 'getDataRange' of null
json    @ Code.gs:4

The code I`m using is the following:

 function json() {
      const spreadsheet = SpreadsheetApp.getActiveSpreadsheet()
      const sheet = spreadsheet.getSheetByName("APItest")
      const data = sheet.getDataRange().getValues()
      const jsonData = convertToJson(data)
      return ContentService
            .createTextOutput(JSON.stringify(jsonData))
            .setMimeType(ContentService.MimeType.JSON)
    }

I already tried to change the getSheetID but also didn`t work

Answer 1

Probably you're getting null value after the execution of

const sheet = spreadsheet.getSheetByName("APItest")

And That's why you get the error in the next statement. make sure that the sheet is not null.