
DART Cookbook
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Dart gives us many flexible and succinct ways to build objects through constructors:
With optional arguments, such as in the Person
constructor where salary
is optional:
class Person{ String name; num salary Person(this.name, {this.salary}); }
With named constructors (a bonus for readable self-documenting code), for example, where a BankAccount
for the same owner as acc
is created:
BankAccount.sameOwner(BankAccount acc): owner = acc.owner;
With const
constructors, as shown in the following code:
class ImmutableSquare { finalnum length; static finalImmutableSquare ONE = const ImmutableSquare(1); constImmutableSquare(this.length); }
However, modern modular software applications require more flexible ways to build and return objects, often extracted into a factory design pattern (for more information, refer to http://en.wikipedia.org/wiki/Factory_(object-oriented_programming)). Dart has this pattern built right into the language with factory constructors.
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