Returns the string value of the environment declaration name.
Returns the string value of the environment declaration name.
Environment declarations are provided by the surrounding system compiling or running the Dart program. Declarations map a string key to a string value.
If name is not declared in the environment, the result is instead defaultValue.
Example of getting a value:
const String.fromEnvironment("defaultFloo", defaultValue: "no floo")
Example of checking whether a declaration is there at all:
var isDeclared = const String.fromEnvironment("maybeDeclared") != null;