ZBasic System Library
271
ZBasic Microcontrollers
Type
Function returning Single
Invocation
Rnd()
Discussion
This function will return a pseudo-random value in the range of 0.0 to 1.0. The first time that Rnd() is
called after the processor starts up the pseudo-random number generator is initialized with a seed value.
The sequence of values returned will be repeatable when starting from the same seed.
You can alter the sequence of returned values in two ways. Firstly, you can set the value of
Register.SeedPRNG. The next call to Rnd() will initialize the pseudo-random number generator with
that seed value before returning the first random value. The second way to modify the sequence is to call
the Randomize() subroutine. Doing so will initialize the pseudo-random number generator with the
current value of Register.RTCTick. This provides a way to introduce some non-repeatability into the
sequence of values returned by Rnd(). It is especially effective if the time at which Randomize() is
called is controlled by some external, unpredictable event like a user pressing a key.
Example
Dim i as Integer
' print 10 random values
For i = 1 to 10
Debug.Print CStr(Rnd())
Next
Compatibility
BasicX does not support Register.seedPRNG. Instead, it has a system global variable named
seedPRNG. This built-in variable is also supported in ZBasic for compatibility.
See Also
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