ParagraphTextItem
の DataValidation。
// Add a paragraph text item to a form and require the answer to be at least 100 characters. var paragraphTextItem = form.addParagraphTextItem().setTitle('Describe yourself:'); var paragraphtextValidation = FormApp.createParagraphTextValidation() .setHelpText(“Answer must be more than 100 characters.”) .requireTextLengthGreaterThanOrEqualTo(100).build(); paragraphTextItem.setValidation(paragraphtextValidation);