HP 3000 Manuals HP 3000 Manuals
Prefix Increment and Decrement Operators
The prefix increment or decrement operator increments or decrements its
operand before using its value.
Syntax
++ unary-expression
-- unary-expression
Description
The operand for the prefix increment ++ or the prefix decrement --
operator must be a modifiable lvalue with scalar type. The result is not
an lvalue.
The operand of the prefix increment operator is incremented by 1. The
resulting value is the result of the unary-expression.
The prefix decrement operator behaves the same way as the prefix
increment operator except that a value of one is subtracted from the
operand.
For any expression E, the unary expressions ++E and (E+=1) yield the same
result. If the value of X is 2, after the expression A=++X is evaluated,
A is 3 and X is 3.
Pointers are assumed to point into arrays. Incrementing (or
decrementing) a pointer causes the pointer to point to the next (or
previous) element. This means, for example, that incrementing a pointer
to a structure causes the pointer to point to the next structure, not the
next byte within the structure. (Refer also to "Additive Operators" for
information on adding to pointers.)