Question

The loop in the function require() takes 3 conditions, a > b or “a” or “b” aren’t digits. Even when I don’t satisfy the conditions and put 2 integers in, it just loops once again.

Also when I put in a character then it just endlessly loops “Enter minimum number Enter maximum number” ignoring the cins. Anyone know why? I’m a beginner so this is probably really obvious

#include <iostream>
#include <cmath>
#include <cstdlib>
#include <ctime>

using namespace std;

int random(int minN, int maxN)   //generates random number within specified range
{
    srand (time(NULL));
    int x = (maxN - minN);
    int y = minN + (rand() % (x+1));
    return y;
}

int require()        //makes sure a < b and both are digits
{
    int a,b;
    do {
    cout << "Enter minimum number" << endl;
    cin >> a;
    cout << "Enter maximum number. Note: Has to be greater or equal to minimum." << endl;
    cin >> b;
    } while (a > b || !isdigit(a) || !isdigit(b));

    return random(a,b);
}

int main()
{
    cout << require() << endl;
}

Answer 1

You should not use isdigit as this relates to a particular character is a digiti. Instead the loop should look like this:

int require()        //makes sure a < b and both are digits
{
    validNumbers = true;
    do
    {
       cout << "Enter minimum number" << endl;
       cin.clear();
       cin >> a;
    } while (cin.fail());

    do
    {
       cout << "Enter maximum number. Note: Has to be greater or equal to minimum."
            << endl;
       cin.clear();
       cin >> b;
    } while (cin.fail() || a > b);

    return random(a,b);
}

PS: You only need to call srand (time(NULL)); once at the start of the program.