Use variables declared inside do-while loop in the condition [duplicate]

Answer 1

Double, which must be changed to an unreserved word (thanks Chad), needs to be declared outside the do's scope in order to be used in the while condition.

int i = 0;
int d = 0;
do{
    d = i * 2;
    cout << d;
    i++;
} while (d < 100);