gmp_prob_prime
PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8
gmp_prob_prime - Check if number is "probably prime"
Manual
gmp_prob_prime(
GMP|int|string$num,
[int$repetitions = 10] ): int
The function uses Miller-Rabin's probabilistic test to check if a number is a prime.
Parameters
- num
-
The number being checked as a prime.
A GMP object, an int or a numeric string.
- repetitions
-
Reasonable values of repetitions vary from 5 to 10 (default being 10); a higher value lowers the probability for a non-prime to pass as a "probable" prime.
A GMP object, an int or a numeric string.
Return Values
If this function returns 0, num is definitely not prime. If it returns 1, then num is "probably" prime. If it returns 2, then num is surely prime.