# gmp_prob_prime

(PHP 4 >= 4.0.4, PHP 5)

gmp_prob_primeCheck if number is "probably prime"

### 说明

int gmp_prob_prime ( resource \$a [, int \$reps = 10 ] )

The function uses Miller-Rabin's probabilistic test to check if a number is a prime.

### 参数

a

The number being checked as a prime.

reps

Reasonable values of reps vary from 5 to 10 (default being 10); a higher value lowers the probability for a non-prime to pass as a "probable" prime.

### 返回值

If this function returns 0, a is definitely not prime. If it returns 1, then a is "probably" prime. If it returns 2, then a is surely prime.

### 范例

Example #1 gmp_prob_prime() example

``` <?php// definitely not a primeecho gmp_prob_prime("6") . " ";// probably a primeecho gmp_prob_prime("1111111111111111111") . " ";// definitely a primeecho gmp_prob_prime("11") . " ";?> ```

```0
1
2
```

• gmp_abs
• gmp_and
• gmp_clrbit
• gmp_cmp
• gmp_div
• gmp_divexact
• gmp_div_q
• gmp_div_qr
• gmp_div_r
• gmp_fact
• gmp_gcd
• gmp_gcdext
• gmp_hamdist
• gmp_init
• gmp_intval
• gmp_invert
• gmp_jacobi
• gmp_legendre
• gmp_mod
• gmp_mul
• gmp_neg
• gmp_nextprime
• gmp_or
• gmp_perfect_square
• gmp_popcount
• gmp_pow
• gmp_powm
• gmp_prob_prime
• gmp_random
• gmp_scan0
• gmp_scan1
• gmp_setbit
• gmp_sign
• gmp_sqrt
• gmp_sqrtrem
• gmp_strval
• gmp_sub
• gmp_testbit
• gmp_xor
• PHP MySQL HTML CSS JavaScript MSSQL AJAX .NET JSP Linux Mac ASP 服务器 SQL jQuery C# C++ java Android IOS oracle MongoDB SQLite wamp 交通频道