Random double generation between a range in dart

The nextDouble returns a value between 0 and 1 (not included). So, if you want a number in the range a (included) to b (not included), you can just do:

double doubleInRange(Random source, num start, num end) => 
    source.nextDouble() * (end - start) + start;

print(doubleInRange(random, a, b));

No, there isn't, but it easy to recreate it since nextInt takes only a max value (exclusive).

nextDouble() * max