问题
In PHP, we have the choice of mt_rand() and rand() where mt_rand() uses the Mersenne Twister algorithm and rand() uses the libc random generator.
I would like to choose a random item out of an array using array_rand. However, does array_rand use the Mersenne Twister algorithm?
It is quite simple to implement my own array_rand using mt_rand, but if array_rand uses the Mersenne Twister, then all the better.
回答1:
It appears that array_rand uses php_rand() internally, which appears to be the good old non-mt version.
回答2:
It does now, as of PHP 7.1; see this RFC and this bug report for more details.
回答3:
It was probably not the case since results from array_rand() used to be not random at all. It's been fixed in latest releases (see Vaxquis's answer for the details).
来源：https://stackoverflow.com/questions/10101923/does-array-rand-use-the-mersenne-twister-algorithm