random(); // random float between 0 (inclusive) and 1 (exclusive)
random(['win', 'mac', 'lin'], [70, 20, 10]);  // random 70% - 'win', 20% - 'mac', 10% - 'lin'
random(['win', 'mac', 'lin'], [2, 1, 1]);  // random 50% - 'win', 25% - 'mac', 25% - 'lin'
random(['win', 'mac', 'lin'], [.9, .05, .05]);  // random 50% - 'win', 25% - 'mac', 25% - 'lin'
random(true);  // random true or false
random(false);  // random true or false
random(1);  // random 0 or 1
random(1.999);  // random 0 or 1 or 2
random([0, 1, 2, 3]);  // random 0 or 1 or 2 or 3
random(['a', 'b']);  // random 'a' or 'b'
random(1, 2);  // random 1 or 2
random(1, 4);  // random 1 or 2 or 3 or 4