Implementing Dart Patterns

Contents

• Pattern Selection Strategy
• Switch Statements vs. Expressions
• Core Pattern Implementations
• Workflows
• Examples

Pattern Selection Strategy

Apply specific pattern types based on the data structure and desired outcome. Follow these conditional guidelines:

• If validating and extracting from deserialized data (e.g., JSON): Use Map and List patterns to simultaneously check structure and destructure key-value pairs.
• If handling multiple return values: Use Record patterns to destructure fields directly into local variables.
• If executing type-specific behavior (Algebraic Data Types): Use Object patterns combined with sealed classes to ensure exhaustiveness.
• If matching numeric ranges or conditions: Use Relational (>=, <=) and Logical-and (&&) patterns.
• If multiple cases share logic: Use Logical-or (||) patterns to share a single case body or guard clause.
• If ignoring specific values: Use the Wildcard pattern (_) or a non-matching Rest element (...) in collections.