Returns the integer value of the given environment declaration name.
The result is the same as would be returned by:
int.parse(const String.fromEnvironment(name, defaultValue: ""),
(_) => defaultValue)
Example:
const int.fromEnvironment("defaultPort", defaultValue: 80)
Source
// The .fromEnvironment() constructors are special in that we do not want
// users to call them using "new". We prohibit that by giving them bodies
// that throw, even though const constructors are not allowed to have bodies.
// Disable those static errors.
//ignore: const_constructor_with_body
//ignore: const_factory
external const factory int.fromEnvironment(String name, {int defaultValue});