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Records

Records in Flutter are data structures introduced in Dart 3.0 that allow multiple values to be stored in a single object without needing to create a new class. They make it easy to store and pass groups of data, such as function results, in a simple and readable way.

Records

We can use records to store or pass multiple related values without needing to create a new class. They are especially useful in cases like:

  • Returning multiple values from a function – instead of creating a class or returning a map, we can use a record to pass function results in a concise way.
  • Creating temporary data structures – records are great for storing data that is only needed in a single place or context.
  • Replacing tuples – with records that have named fields, we can write more readable code, eliminating the need to refer to positions (indexes) in a tuple.

Differences between a record and a map

Similarities

  • Data Storage: Both structures allow storing multiple values.
  • Access to Values: Both enable accessing values using identifiers (named positions in Record and keys in Map).
  • Usage in Dart: Both are available and useful for representing data in Dart, although suited for different scenarios.

Differences

  1. Data Structure:

    • Record: Fixed structure with a defined number of positions that cannot be dynamically modified.
    • Map: Dynamic key-value structure, where pairs can be freely added or removed.

  2. Typing:

    • Record: Statically typed, allowing performance optimization and reducing type errors.
    • Map: Dynamic and flexible, allowing values of any type.

  3. Access to Values:

    • Record: Accessed by named positions (e.g., .name) or position indices (e.g., $1, $2).
    • Map: Accessed by keys, which can be any type, e.g., map['name'].

  4. Flexibility and Modification:

    • Record: The number and names of elements cannot be changed after creation.
    • Map: Key-value pairs can be dynamically added, removed, and modified.

  5. Purpose:

    • Record: Ideal for representing complex but fixed data structures (e.g., an object with defined fields).
    • Map: Suitable when flexibility is needed, such as handling JSON data.

  6. Optimized Performance:

    • Record: Due to static typing, Record is more optimized for performance.
    • Map: Less optimized because of its flexibility and dynamic nature.