为什么 rand() 一直给出相同的值？

Question

Every time the function gets called, it's always "number = 5". The number always stays 5. I checked it already to make sure that srand is only ran once some I'm confused. This is a function inside of a class.

int playType::getComputerMove(){
    int number;
    if(gamesPlayed == 0){
        srand(time(NULL));
    }
    number = rand() % 1 + 5;
    return number;
}

Answer 1

Your issue is with the order of operations. rand() % 1 is resolved before the adding five. Since n % 1 = 0 , you will always get 5. Essentially, what is happening is this:

number = (rand() % 1) + 5;

In order to fix this, you will want to add parenthesis this way:

number = rand() % (1 + 5);