Srand (Time (NULL)) in C language; What is the meaning of this remark (especially NULL)

This is a two function!

Srand function

One is the Srand function! This is used before calling the rand () function! Rand () is a function that produces a random number! And Srand is a function that sets the seed of a random number! Usually these two functions are used together! To complete the function of generating random numbers!

Time function

and time (NULL) The return value of this function is the parameter of the Srand function! This means that the current system time as a random number of seeds to generate random numbers! As for null, this argument is simple because the word returns to the current time of the long second, only set to NULL to get the system time!

Srand (Time (NULL)) in C language; What is the meaning of this remark (especially NULL)