Random Class Reference

A random number generator. More...

#include <juce_Random.h>

Collaboration diagram for Random:

Public Member Functions
	Random (int64 seedValue) noexcept
	Creates a Random object based on a seed value. More...
	Random ()
	Creates a Random object using a random seed value. More...
	~Random () noexcept
	Destructor. More...
void	combineSeed (int64 seedValue) noexcept
	Merges this object's seed with another value. More...
void	fillBitsRandomly (void *bufferToFill, size_t sizeInBytes)
	Fills a block of memory with random values. More...
void	fillBitsRandomly (BigInteger &arrayToChange, int startBit, int numBits)
	Sets a range of bits in a BigInteger to random values. More...
int64	getSeed () const noexcept
	Returns the RNG's current seed. More...
bool	nextBool () noexcept
	Returns the next random boolean value. More...
double	nextDouble () noexcept
	Returns the next random floating-point number. More...
float	nextFloat () noexcept
	Returns the next random floating-point number. More...
int	nextInt () noexcept
	Returns the next random 32 bit integer. More...
int	nextInt (int maxValue) noexcept
	Returns the next random number, limited to a given range. More...
int	nextInt (Range< int > range) noexcept
	Returns the next random number, limited to a given range. More...
int64	nextInt64 () noexcept
	Returns the next 64-bit random number. More...
BigInteger	nextLargeNumber (const BigInteger &maximumValue)
	Returns a BigInteger containing a random number. More...
void	setSeed (int64 newSeed) noexcept
	Resets this Random object to a given seed value. More...
void	setSeedRandomly ()
	Reseeds this generator using a value generated from various semi-random system properties like the current time, etc. More...

Static Public Member Functions
static Random &	getSystemRandom () noexcept
	The overhead of creating a new Random object is fairly small, but if you want to avoid it, you can call this method to get a global shared Random object. More...

Private Attributes
int64	seed

Detailed Description

A random number generator.

You can create a Random object and use it to generate a sequence of random numbers.

Constructor & Destructor Documentation

Random() [1/2]

Random::Random ( int64  seedValue )

explicitnoexcept

Creates a Random object based on a seed value.

For a given seed value, the subsequent numbers generated by this object will be predictable, so a good idea is to set this value based on the time, e.g.

new Random (Time::currentTimeMillis())

Random() [2/2]

Random::Random

(

)

Creates a Random object using a random seed value.

Internally, this calls setSeedRandomly() to randomise the seed.

~Random()

Random::~Random ( )

noexcept

Destructor.

Member Function Documentation

combineSeed()

void Random::combineSeed ( int64  seedValue )

noexcept

Merges this object's seed with another value.

This sets the seed to be a value created by combining the current seed and this new value.

fillBitsRandomly() [1/2]

void Random::fillBitsRandomly	(	void *	bufferToFill,
		size_t	sizeInBytes
	)

Fills a block of memory with random values.

fillBitsRandomly() [2/2]

void Random::fillBitsRandomly	(	BigInteger &	arrayToChange,
		int	startBit,
		int	numBits
	)

Sets a range of bits in a BigInteger to random values.

getSeed()

int64 Random::getSeed ( ) const

inlinenoexcept

Returns the RNG's current seed.

getSystemRandom()

static Random& Random::getSystemRandom ( )

staticnoexcept

The overhead of creating a new Random object is fairly small, but if you want to avoid it, you can call this method to get a global shared Random object.

It's not thread-safe though, so threads should use their own Random object, otherwise you run the risk of your random numbers becoming.. erm.. randomly corrupted..

Referenced by JuceWindowIdentifier::getImprobableWindowNumber(), and File::getVolumeSerialNumber().

nextBool()

bool Random::nextBool ( )

noexcept

Returns the next random boolean value.

nextDouble()

double Random::nextDouble ( )

noexcept

Returns the next random floating-point number.

Returns

a random value in the range 0 (inclusive) to 1.0 (exclusive)

nextFloat()

float Random::nextFloat ( )

noexcept

Returns the next random floating-point number.

Returns

a random value in the range 0 (inclusive) to 1.0 (exclusive)

nextInt() [1/3]

int Random::nextInt ( )

noexcept

Returns the next random 32 bit integer.

Returns

a random integer from the full range 0x80000000 to 0x7fffffff

nextInt() [2/3]

int Random::nextInt ( int  maxValue )

noexcept

Returns the next random number, limited to a given range.

The maxValue parameter may not be negative, or zero.

Returns

a random integer between 0 (inclusive) and maxValue (exclusive).

nextInt() [3/3]

int Random::nextInt ( Range< int >  range )

noexcept

Returns the next random number, limited to a given range.

Returns

a random integer between the range start (inclusive) and its end (exclusive).

nextInt64()

int64 Random::nextInt64 ( )

noexcept

Returns the next 64-bit random number.

Returns

a random integer from the full range 0x8000000000000000 to 0x7fffffffffffffff

Referenced by JuceWindowIdentifier::getImprobableWindowNumber().

nextLargeNumber()

BigInteger Random::nextLargeNumber

(

const BigInteger &

maximumValue

)

Returns a BigInteger containing a random number.

Returns

a random value in the range 0 to (maximumValue - 1).

setSeed()

void Random::setSeed ( int64  newSeed )

noexcept

Resets this Random object to a given seed value.

setSeedRandomly()

void Random::setSeedRandomly

(

)

Reseeds this generator using a value generated from various semi-random system properties like the current time, etc.

Because this function convolves the time with the last seed value, calling it repeatedly will increase the randomness of the final result.

Member Data Documentation

seed

int64 Random::seed

private

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The documentation for this class was generated from the following file:

• juce_Random.h