An integer literal is a primary expression of the form
decimal-literal
It is a non-zero decimal digit (1, 2, 3, 4, 5, 6, 7, 8, 9), followed by zero or more decimal digits (0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
int d = 42;
octal-literal
It is the digit zero (0) followed by zero or more octal dig...