How to insert a line every 10 numbers displayed in C++?

I am trying to insert a line every 10 numbers displayed but when I run this and enter -29 and 29, not a single line shows. Please help and thank you

int start;
int end;
     
do 
{
    cout << "Please enter a number between -30 and 0: ";
    cin >>start;
} while(start > 0 || start < -30);
    
do 
{
    cout << "Pleaes enter a number between 15 and 30: ";
    cin >> end;
} while(end < 15 || end > 30);
        
for (int i = start; i <= end; i++)
{
    if (i++ % 10 == 0)
    {
        cout << "----------"<<endl;
    }
    else
        cout << start << " " << end <<endl;
}

>Solution :

i is incremented twice. Do not increment it again in the if condition, and just use the following:

if (i % 10 == 0)