Dart LanguageBeginner10 XP2 min read
What is Dart's cascade notation (..) and when should you use it?
TL;DR: The cascade operator (..) allows chaining multiple operations on the same object without repeating the variable name. It returns the original object, not the result of each operation.
Full Answer
Cascades are syntactic sugar for calling multiple methods or setting multiple properties on the same object. Perfect for the Builder pattern, configuring complex objects, or Paint() configurations in CustomPainter.
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?.. is the null-safe cascade — if the object is null, all cascaded operations are skipped.
Code Examples
dartCascade notation examples
Output
[1, 2, 3, 4, 5]
Interview Tip
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Cascades are read-only syntax sugar — they don't affect performance. The compiler translates them to the same imperative code. Use them whenever you're configuring an object with multiple properties.
#cascade#method-chaining#syntax#builder-pattern