In Lua, you can find the size of an array by using the # operator.
Here's an example:
my_array = {1, 2, 3, 4, 5}
print(#my_array)
This will output 5, which is the size of the array.
Another example:
my_array = {"apple", "banana", "orange"}
print(#my_array)
This will output 3, which is the size of the array.
Note that this method works only with sequential arrays whose indices start from 1 and go up to a specific value. If you have an associative array, the # operator will not work accurately.