PHP random number generation and usage analysis_PHP tutorial

[php100 translation] In the previous article we introduced how to use
to get seven results in the second run

Maybe you will ask, PHP random Can numbers only do these boring things? rand() does not seem to be that important; you are wrong, think about the verification codes that can be seen everywhere, the random article extraction of some CMS systems, download address allocation, etc. Random numbers are in these It plays an important role in applications; in addition, in the fields of security and algorithms, many applications of random numbers are also worthy of our in-depth study, such as encryption and congruence structures.