Console.log VS Logger.log

To display information in the console of Google Sheets, you have 2 options, console.log and Logger.log.

These 2 possibilities may seem similar at first glance, however, that's not the case...

On this page, you'll discover why console.log is a much better choice.

Text

A first test with text:

function test() {
  console.log('Sheets-Pratique');
  Logger.log('Sheets-Pratique');
}

In this case, the result is identical:

Multiple values

A test with multiple values:

function test() {
  console.log('console', 1, 2, 3, 4, 5);
  Logger.log('Logger', 1, 2, 3, 4, 5);
}

You can see that console.log displays all values while Logger.log only displays the first one:

Numbers

A test with numbers:

function test() {
  console.log(12);
  console.log(12.34);
  Logger.log(12);
  Logger.log(12.34);
}

You can see that console.log displays the values correctly while Logger.log displays an unnecessary decimal for 12:

Objects

A test with objects:

function test() {
  console.log([1, 2, 3, [4], {5: 6}]);
  Logger.log([1, 2, 3, [4], {5: 6}]);
}

You can see that the display of data is not identical (not to mention the annoying unnecessary decimal in Logger.log):

JavaScript

A test with a custom dialog box:

function test() {
  SpreadsheetApp.getUi().showModalDialog(HtmlService.createHtmlOutput(`<script>console.log(123);Logger.log(123);</script></body></html>`), 'Test ...');
}

Unsurprisingly, you can see in the browser console that console.log displays the value while Logger.log returns an error:

Whether it's a custom dialog box or a custom sidebar, the script contained in these elements is JavaScript, and only console.log can work in this case.

Console.warn and console.error

In addition, a test with different methods:

function test() {
  console.log('Sheets-Pratique');
  console.info('Sheets-Pratique');
  console.warn('Sheets-Pratique');
  console.error('Sheets-Pratique');
  Logger.log('Sheets-Pratique');
}

You can see that console.warn and console.error display a message with a more critical color: