CommonRandom function

Random CommonRandom([ int? seed ])

Creates a Random number generator.

Every time you reinstall your app, a Random() instance is initialized with the same starting conditions, leading to the same sequence of "random" numbers. To ensure you get a different sequence each time the app runs, this function uses the current timestamp as a seed by default.

NOTE: If you call CommonRandom() multiple times in quick succession (within the same millisecond), they might be seeded with the same value and thus produce the same sequence of numbers.

To get distinct random values throughout your app, you should create a single instance of Random and reuse it.

Example:

final random = CommonRandom();
print(random.nextInt(100)); // A random number
print(random.nextBool());   // A random boolean

You can also provide a fixed seed to get a predictable sequence of numbers, which is useful for testing.

Implementation

// ignore: non_constant_identifier_names
Random CommonRandom([int? seed]) =>
    // Algorithm:
    // 1. Check if a `seed` value is provided.
    // 2. If `seed` is null, use `DateTime.now().millisecondsSinceEpoch` as the seed.
    //    This makes the random sequence unique for each run.
    // 3. If `seed` is not null, use the provided value. This creates a predictable
    //    sequence, which is useful for testing or when reproducible "randomness" is needed.
    // 4. Create and return a `Random` instance with the determined seed.
    Random(seed ?? DateTime.now().millisecondsSinceEpoch);