How to create a default empty function in Dart

user_11235449 0
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I want to pass a callback as a constructor parameter and if the callback is null I want to give a default value. But I don't know a proper way how to generate an empty function in Dart.

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dart function constructor
2 Answers

You need to wrap the callback in parentheses:

this.callback = callback ?? (() {})

otherwise the braces would be considered as the body of the constructor.

user_70711520

Just remove the arrow function so you have this.callback = callback ?? () {}

user_144011670
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