Expose the probability of falling TRUE in an array of 100 elements with FALSE?

Question

PHP

I tried to google, they use the mt_rand functions everywhere and it’s not clear what is involved with them. I think that in my case, since I only need to return TRUE or FALSE , it’s easier to take an array of 100 elements, we set the probability of TRUE falling out to be 30%, which means that in the array we have 30 elements with the TRUE value. We shuffle the array several times, and then we get a random index from there, look at the value, voila.
However, I'm wondering if there is anything else in this spirit that is simple and reliable? Will the result be affected if the array has 10, 1,000, or 1,000,000 elements?

Answer 1

random index

So you know how to take randomly. And in range too.
Then - throw a random from 0 to 100. If <30 - then True, otherwise - false.
There is nowhere more reliable.
The array is redundant - this is a waste of memory that no one needs.

Answer 2

get a random index from there

How good is the random index? This will affect the quality of the sample.
Wouldn’t it be easier to immediately compare the random index with the given value