int rand(void );Returns a pseudo-random value between 0 and RAND_MAX. If you want a random number between 5 and 15, for example, use rand()%10 + 5.
Remember to seed the random number generator before use with srand().
Here are two handy functions that use rand(). One returns a random integer less than a specified maximum value, the other does the same but returns a real value.
Example 1. rand example functions function randomint($max = 100) {
static $startseed = 0;
if (!$startseed) {
$startseed = (double)microtime()*getrandmax();
srand($startseed);
}
return (rand()%$max);
}
function random($max = 1) {
static $startseed = 0;
if (!$startseed) {
$startseed = (double)microtime()*getrandmax();
srand($startseed);
}
return ((rand()/getrandmax())*$max);
}
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See also srand() and getrandmax().