C++ provides several assignment operators for abbreviating assignment expressions. For example, the statement
c = c + 3;
can be abbreviated with the addition assignment operator += as
c += 3;
which adds the value of the expression on the operator’s right to the value of the variable on the operator’s left and stores the result in the left-side variable. Any statement of the form
variable = variable operator expression;
in which the same variable appears on both sides of the assignment operator and operator is one of the binary operators +
, -
, *
, /
, or %
(or a few others we’ll discuss later in the text), can be written in the form
variable operator= expression;
Thus the assignment c += 3
adds 3
to c
. Figure 4.13 shows the arithmetic assignment operators, sample expressions using these operators and explanations.