Random with probability for elements?

Question

PHP

Hello, how can I make a function that will display a random result from an array? These elements have a drop chance.

[
 {
   "id" : 1,
   "chance" : 10
 },
 {
   "id" : 20,
   "chance" : 70
 },
 {
   "id" : 34,
   "chance" : 20
 }
]

There is one theory. Create a temporary array of 100 elements and duplicate id [1...1, 20 .... 20, 34 .... 34] there. But I don't think this is the best solution. Tell me please

Answer 1

Sea of ​​solutions. Depends on your imagination.
I would do this:
1. Calculate the current drop chance, something like this mt_rand(0, 10000) / 100.
2. Filter the array to remove elements with a chance lower than step 1.
3. Run array_shuffle, for example.
4. Select the desired number of elements.
If the chance is needed for each element to count separately, then accordingly it happens during filtering. Fortunately, there is filtering with a callback: php.net/manual/ru/function.array-filter.php