C Additive Operators
The additive operators perform addition (+) and subtraction (–).
additive-expression + multiplicative-expression
additive-expression – multiplicative-expression
Although the syntax for additive-expression includes multiplicative-expression, this does not imply that expressions using multiplication are required. See the syntax in C Language Syntax Summary, for multiplicative-expression, cast-expression, and unary-expression.
The operands can be integral or floating values. Some additive operations can also be performed on pointer values, as outlined under the discussion of each operator.
The additive operators perform the usual arithmetic conversions on integral and floating operands. The type of the result is the type of the operands after conversion. Since the conversions performed by the additive operators do not provide for overflow or underflow conditions, information may be lost if the result of an additive operation cannot be represented in the type of the operands after conversion.