gmp_nextprime
(PHP 5 >= 5.2.0)
gmp_nextprime — Find next prime number
说明
resource gmp_nextprime ( int $a )Find next prime number
参数
- a
-
可以是一个 GMP 数据 resouce,或一个可以转换为数值的字符串。
返回值
Return the next prime number greater than a, as a GMP number.
范例
Example #1 gmp_nextprime() example 以上例程会输出:
<?php
$prime1 = gmp_nextprime(10); // next prime number greater than 10
$prime2 = gmp_nextprime(-1000); // next prime number greater than -1000
echo gmp_strval($prime1) . "
";
echo gmp_strval($prime2) . "
";
?>
11
-997
注释
Note:
This function uses a probabilistic algorithm to identify primes and chances to get a composite number are extremely small.