random.h

This interface exports functions for generating pseudorandom numbers.
Functions
randomInteger(low, high) Returns a random integer in the range low to high, inclusive.
randomReal(low, high) Returns a random real number in the half-open interval [low .. high).
randomChance(p) Returns true with the probability indicated by p.
setRandomSeed(seed) Sets the internal random number seed to the specified value.

Function detail


int randomInteger(int low, int high);
Returns a random integer in the range low to high, inclusive.

Usage:

n = randomInteger(low, high);

double randomReal(double low, double high);
Returns a random real number in the half-open interval [low .. high). A half-open interval includes the first endpoint but not the second, which means that the result is always greater than or equal to low but strictly less than high.

Usage:

d = randomReal(low, high);

bool randomChance(double p);
Returns true with the probability indicated by p. The argument p must be a floating-point number between 0 (never) and 1 (always). For example, calling randomChance(.30) returns true 30 percent of the time.

Usage:

if (randomChance(p)) . . .

void setRandomSeed(int seed);
Sets the internal random number seed to the specified value. You can use this function to set a specific starting point for the pseudorandom sequence or to ensure that program behavior is repeatable during the debugging phase.

Usage:

setRandomSeed(seed);