The first substatement of an if statement may be followed by the keyword else
. The substatement after the else
keyword will be executed when the condition is falsey (that is, when the first substatement is not executed).
int x;
std::cin >> x;
if (x%2 == 0) {
std::cout << "The number is even\n";
} else {
std::cout << "The number is odd\n";
}