Random()
Random()
- Description
Use function random() will generate pseudo random numbers.
- Syntax
random(max) random(min, max)
- Parameter
min - The minimum value of a random number, which is included in the random number. (optional) max - The maximum value of a random number, which is not included in the random number.
- Return
A random number between min and max-1(the data type is long ).
- Note
If you need a truly random number to be generated in a random() sequence, when its subsequence is being executed , use function randomSeed() to preset an absolute random input, for example, the returned value of function analogRead() in a disconnected pin.
On contrary, sometimes, accurate repeat of the pseudo random bumber is also useful. This can be completed before the start of a random sequence, through calling a randomSeed() with a fixed value.
- Example
long randNumber; void setup(){ Serial.begin(9600); //If the analog input pin 0 is disconnected, it will imitate noise randomly. //It will call randomSeed() to generate when each run of the code. //Different seed values. //RandomSeed() will randomly disturb function random. randomSeed(analogRead(0)); } void loop() { //Print a random number between 0 to 299. randNumber = random(300); Serial.println(randNumber); //Print a random number between 10 to 19. randNumber = random(10, 20); Serial.println(randNumber); delay(50); }