"Hello! '{Isn''t}' this a wonderful day?"

becomes the following Dart String:

"Hello! {Isn't} this a wonderful day?"

Messages with numbers and currencies

Numbers, including those that represent currency values,
are displayed very differently in different locales. 
The localizations generation tool in flutter_localizations uses the
intl package’s NumberFormat class
to properly format numbers based on the locale and the
desired format.

The int, double, and number types can use any of the
following NumberFormat constructors:

compact

“1.2M”

compactCurrency*

“$1.2M”

compactSimpleCurrency*

“$1.2M”

compactLong

“1.2 million”

currency*