can anyone explain this function line by line?

Question

function make_seed()
{
list($usec,$sec)=explode(' ',microtime ());
return(double)$sec+((double)$usec*100000);
}

Answer 1

1: keyword of making a function + the name of your function + ()
2: open the function
3: getting an arraylist + getting the arraylist as a list of strings using the function microtime()
4: return $sec as a double integer + return $usec*100000 as a double integer
5: close the definition of the function