### Clarify rand()

I am using the rand() function, but I need to create a range. Can someone clarify ranges?

 ``123456789101112`` `````` #include #include #include #include using namespace std; int main() { int x x = rand() //I want this number to be in the range of -12 to +12 }``````
http://www.cplusplus.com/reference/clibrary/cstdlib/rand/

Firstly, you need to seed the rand() function with srand(). Computers don't really know how to call random numbers.

initialize a random seed number with
`srand(time(NULL)); // This code gives the current time to srand() `

To get a range between numbers you use the modulo operator.
`x = rand() % 10 ; // This will give you a number between 0 to 9 `

`x = rand() % 10 + 1; // This will give you a number between 1-10 `

To get a random number is another problem because rand() gives you a number from 0 to RAND_MAX.
`x = rand() % 13; // For range from 0 to 12 `

`x = rand() % 2 == 0 ? x : -x; // This last code says if a random number is generated and is even then, give it a positive number, if not then change it to negative `

HTH

P.S. Don't forget to include ctime or time.h

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