Ceylon Random provides:

• a pseudorandom number generator (DefaultRandom),
• toplevel utility functions to shuffle streams or arrays (randomize and randomizeInPlace), and
• an easy to implement interface for use by third party random number generators (Random).

To generate random numbers, create and use an instance of DefaultRandom:

// Create a random number generator
value random = DefaultRandom();

// Print a pseudorandom Float in the range 0.0 to 1.0:
print (random.nextFloat());

Other simple methods include Random.nextBits(), Random.nextBoolean(), Random.nextByte(), and Random.nextInteger().

Random.nextElement() can be used to generate a random number within a Range:

print(random.nextElement(1..100));
// Sample output: 27

or select a random element from a Sequence:

print(random.nextElement(["heads", "tails"]));
// Sample output: heads

It is also possible to obtain an infinite stream of random values using the methods Random.bits(), Random.booleans(), Random.bytes(), Random.elements(), Random.floats, and Random.integers().

For example, to simulate multiple rolls of a die:

value diceStream => random.elements([*('⚀':6)]);
print(diceStream.take(10));
// Sample output: { ⚂, ⚀, ⚀, ⚂, ⚀, ⚅, ⚁, ⚅, ⚅, ⚁ }

Finally, randomize() and randomizeInPlace() can be used to shuffle a list:

print(randomize {
    for (suit in {"♠", "♥", "♦", "♣"})
    for (rank in {"Ace", "King", "Queen", "Jack",
                  *(10..2)*.string})
    suit + rank
}.take(5));
// sample output: { ♥6, ♣Queen, ♦King, ♥King, ♣10 }