Class Logger

This class allows the developer to write out text to the debugging logs.

Methods

Method	Return type	Brief description
`clear()`	`void`	Clears the log.
`getLog()`	`String`	Returns a complete list of messages in the current log.
`log(data)`	`Logger`	Writes the string to the logging console.
`log(format, values)`	`Logger`	Writes a formatted string to the logging console, using the format and values provided.

Detailed documentation

`clear()`

Clears the log.

`getLog()`

Returns a complete list of messages in the current log. This method can be used to save or email the entire log output generated during script execution.

// Generate a log, then email it to the person who ran the script.
var files = DriveApp.getFiles();
while (files.hasNext()) {
  Logger.log(files.next().getName());
}
var recipient = Session.getActiveUser().getEmail();
var subject = 'A list of files in your Google Drive';
var body = Logger.getLog();
MailApp.sendEmail(recipient, subject, body);

Return

String — the log from the logging console

`log(data)`

Writes the string to the logging console. To view the logged output, select View > Show logs. This can be very useful for debugging scripts.

Parameters

Name	Type	Description
`data`	`Object`	the message to log

Return

Logger — the Logger, for chaining.

`log(format, values)`

Writes a formatted string to the logging console, using the format and values provided. The string can include multiple %s placeholders, which are replaced with corresponding values from the list of arguments, converted to strings.

// Log the number of Google Groups you belong to.
var groups = GroupsApp.getGroups();
Logger.log('You are a member of %s Google Groups.', groups.length);

Parameters

Name	Type	Description
`format`	`String`	a format string that contains as many instances of `%s` as the number of `values` arguments
`values`	`Object...`	a variable number of values to insert into the format string

Return

Logger — the Logger, for chaining