The last loop example showed an operator which was not yet introduced,
namely ` ++`. Its effect is to increment its operand, ` f` in
the example, by ` 1`. Similarly, ` f-` would decrease ` f`
by ` 1`.

The increment and decrement operators can be used in a postfix notation,
as in the example, or a prefix notation, as in ` -f`. The
difference between these notations is the value returned by the
expression. The postfix notation returns the value of the variable
before the modification; in prefix notation, the value of the expression
the new value of the variable.

Given the fact that the value of a compound expression is the value of
the last expression contained in the compound, ` f++` is identical to

{ int g = f; f = f + 1; g; }

and ` -f` equals

{ f = f - 1; }

The last kind of operators to be introduced are the modifying assignment
operators. For example, `f = f + x`

can be written as ` f +=
x`. The same is true for every other binary operator. The precedence of
these operators is equal to that of the normal assignment (they are the
`etc' in table 2.3).