I'm new to C#, I tried to write a program that checks if the number entered by the user is prime or not, and I got this error after running it

Question

The eroor is :Exception Unhadled :System.DivideByZeroException: 'Attempted to divide by zero.'And this is the code :

Console.Write("Enter the number: ");
int A =Convert.ToInt32(Console.ReadLine());
bool flag = false;

if (A < 2)
{
    Console.WriteLine($"{A} is a prime number!! ");
}

for (int i = 0; i < A; i++)
{
    if (A % i == 0) 
    {
        flag = true; break; 
    }
}

if (flag == true) 
{ 
    Console.WriteLine($"{A} is not a prime number!!"); 
}
else 
{ 
    Console.WriteLine($"{A} is a prime number !!"); 
}
Console.ReadKey();

Answer 1

A % 0 will generate a DivideByZeroException. Start your loop with i = 1.

Answer 2

First A % 0 will report an exception, set i=0 to i=1, if you want to get specific exception information, wrap it in the "try...catch" code block

 try{

     for (int i = 1; i < A; i++)
    { 
          if (A % i == 0) 
       {
            flag = true; break; 
       }
    }

    }catch(Exception ex){
         Console.WriteLine("Exception caught: {0}", ex);
    }