Random from array in cpp

Question

I want to know how do random function while the values of the random are from an array that exists in the program (pointer int). My code looks like:

v=rand() %((array[0] - array[size_c]) + 1);

but the value of v does not belong to array. Thank you.

Generate a random index between 0 and `size_c`; then take the value from the array at that index. — Igor Tandetnik, Dec 02 '18 at 18:44
Imagine the array contains two values, an elephant and a seagull. What do you want `v` to be? — Beta, Dec 02 '18 at 18:47

score 0 · Answer 1 · answered Dec 03 '18 at 00:01

int rand_number =  rand() % size;  
v = array[rand_number];

where size is the size of the array and v is your random element from the array

and of course you will need to include cstdlib

and if you want different random each time you run the program you should add this line of code :

  srand (time(NULL));

this will initialize random seed and for the time(NULL) you will have to include time.h

1 Answers1