rand() and srand()

Sometimes you need to generate a random number. In C++, the easiest way to do this is to invoke the rand() function from the cmath library. This method returns a value from [0 - 32767] but you can use a little mathematical

Here are some examples and what they return:

• Code: (rand() % 10)
  Returns: [0 -   9]


• Code: (rand() % 10) + 1
  Returns: [1 -  10]


• Code: (rand() % 100)
  Returns: [0 -  99]


• Code: (rand() % 100) + 1
  Returns: [1 - 100]

Addendum

To make your random numbers more random, you can seed the srand() function with time. Before using one of the constructions above, execute this code:

srand(time(NULL));