Arithmetic Operators

 

The binary arithmetic operators are ₊, _-, _*, _/, and the modulus operator _%. Integer division truncates any fractional part. The expression 

    x % y

produces the remainder when _x is divided by _y, and thus is zero when _y divides _x exactly. For example, a year is a leap year if it is divisible by 4 but not by 100, except that years divisible by 400 are leap years. Therefore 

   if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)        printf("%d is a leap year\n", year);    else

       printf("%d is not a leap year\n", year);

The _% operator cannot be applied to a _float or _double. The direction of truncation for _/ and the sign of the result for _% are machine-dependent for negative operands, as is the action taken on overflow or underflow. 

The binary ₊ and _- operators have the same precedence, which is lower than the precedence of _*, _/ and _%, which is in turn lower than unary ₊ and _-. Arithmetic operators associate left to right. 

Table 2.1 at the end of this chapter summarizes precedence and associativity for all operators.