How to find difference in multidimensional array (google script)?

Question

Google Apps Script

Good afternoon. Help please. comparing two multi-dimensional (multi-line) arrays. You need to find values ​​that are in one column of the table, but not in another table.
There are two tables at the input. In the first table, in the first column, a unique code (for mass comparison, we take it), then a set of specific fields. The structure of the second table: the first column is the date of the entry, the second column is a unique code (we compare it with the first table). Those. for comparison, I take the first column of the first table, and the second column of the second table, and look for codes that are not in the second table (that is, I need unique codes from the first table that are not found in the second table). And the code that I compiled does not show me this difference in any way ... What is the error? What is missing in the code?

//  Данные для первой таблицы
  var sheet = SpreadsheetApp.openById("1CoSKjOmiKqLIU").getSheetByName('contact');
  var numRows = sheet.getLastRow(); 
  var dataRange = sheet.getRange(1, 1, numRows, 5)
  var data = dataRange.getValues();
  
//  Данные для второй таблицы
  var sheetAnswer = SpreadsheetApp.openById("1jjqrpqkG-LdDrVRyXqftJ6NcBts").getSheetByName("Ответы");
  var lastRowAnswer = sheetAnswer.getLastRow(); 
  var dataRangeAnswer = sheetAnswer.getRange(1, 1, lastRowAnswer , 2);
  var dataAnswer = dataRangeAnswer.getValues();


function sendMail() {
  var k = 0
  
  for (var i =0 ; i< dataAnswer.length; i++) {
    for (var q = 0; q < data.length; q++){
 
      if (data[q][0] !== dataAnswer[i][1])
{

// В k, пытаюсь вывести не пересекающиеся значения!
k = data[q][0]
}
    };
};
};

Answer 1

https://stackoverflow.com/questions/51624717/googl...