具有空主体和条件中的赋值的 while 循环

Question

I recently encountered the following construct on an abandoned PHP code project:

while(($my_var = mt_rand(3, 6))%2 != 0);

(Note the empty body of the loop). This ensures that $my_var is assigned either the number 4 or the number 6.

Is there any (measurable, objective) advantage in using the above construction, over something like

$my_var = mt_rand(2, 3) * 2;

(I am particularly wondering why the author chose to include 3 in the randomization range if the result has to be even anyway.)

Answer 1

while(($my_var = mt_rand(3, 6))%2;= 0);

This ensures that $my_var is assigned either the number 4 or the number 6.

As @Oli mentioned in comments, this is very convoluted and hard to read.

And it also has the disadvantage, that you can not really predict how many times it will iterate.

It could (theoretically) “throw the dice” and come up with 5 for the first ten, hundred or thousand iterations... or even never end. (The implementation of mt_rand is likely good enough for that not to happen, but still.)