Suppose I have One set of numbers i.e {1, 6, 3, 5, 7, 9} I want to Generate Random number from this set of number only i.e. a Generated number should be random and should be from these number({1, 6, 3, 5, 7, 9}) only.
standard C/C++ function will also do...
arc4random%(set count) = a random index.
What they are telling you is this. Generate a random number from 0-5. Then use that as an index into the array. Eg if the random # is 2, look at element #2 (the third one since you start at 0) of your list of numbers, which is 3. If the random # is 5, you get 9.
MSalters' comment shows you how to do it in a single expression.
