Java print factorials 1-30

Question

All I am trying to do is print the factorials for numbers 0-30. When I run this, it endlessly prints Factorial=0. Can someone tell me how to correct this?

public static void factor(){

    int n=0;
    int factorial = 1;
    while (n<=0&n<=30)
    {
        n=n++;
      factorial = factorial * n;
      n--;
      System.out.println("Factorial = " + factorial);
    }


}


public static void main(String[] args) {
   factor();
}

Answer 1

You're decrementing n inside the loop, so it it will always flip between 0 and 1. Additionally, an int can't hold numbers so large, and neither can a long. You'll have to use something smarter, like a BigInteger:

int n = 0;
BigInteger factorial = BigInteger.ONE;
while (n <= 30) {
    System.out.printf("Factorial(%d) = %s%n", n, factorial);
    n++;
    factorial = factorial.multiply(BigInteger.valueOf(n));
}