srand

srand -- seed the random number generator

Description

void srand(int seed);

Seeds the random number generator with seed.

  1 
  2 // seed with microseconds since last "whole" second
  3 srand((double)microtime()*1000000);
  4 $randval = rand();
  5       

See also rand(), getrandmax(), mt_rand(), mt_srand() and mt_getrandmax().