Question

I am trying to loop through an array and count the number of prime numbers in it…Simple enough but I am missing something…

count = 0;
for(i =0; i<5; i++)
{
    flag = true;    // is prime
    for (j=2;j<a[i];j++)
    {
        if(a[i] % j == 0)
        {
            flag = false;
        }


    }

    count ++;
}

Answer 1

Change your code to this

flag = true;    // is prime
for (j=2;j<a[i];j++)
{
    if(a[i] % j == 0)
    {
        flag = false;
        break;
    }

}
if (flag) {
   count++;
}   

Once you have counted a non prime you might as well break out of the loop – it is not going to become unprime again with repeated testing