The goog.i18n.MessageFormat Class

goog.i18n.MessageFormat(pattern)

Constructor of MessageFormat.

pattern {string}
The pattern we parse and apply positional parameters to.

.format(namedParameters)

Formats a message, treating '#' with special meaning representing the number (plural_variable - offset).

namedParameters {!Object}
Parameters that either influence the formatting or are used as actual data. I.e. in call to fmt.format({'NUM_PEOPLE': 5, 'NAME': 'Angela'}), object {'NUM_PEOPLE': 5, 'NAME': 'Angela'} holds positional parameters. 1st parameter could mean 5 people, which could influence plural format, and 2nd parameter is just a data to be printed out in proper position.
returns {string}
Formatted message.

.formatIgnoringPound(namedParameters)

Formats a message, treating '#' as literary character.

namedParameters {!Object}
Parameters that either influence the formatting or are used as actual data. I.e. in call to fmt.format({'NUM_PEOPLE': 5, 'NAME': 'Angela'}), object {'NUM_PEOPLE': 5, 'NAME': 'Angela'} holds positional parameters. 1st parameter could mean 5 people, which could influence plural format, and 2nd parameter is just a data to be printed out in proper position.
returns {string}
Formatted message.