Increment and Decrement Operators
Increment and decrement operators — (++, --)
Syntax
++symbol
symbol++
--symbol
symbol__
Arguments
- symbol
A symbol whose value is a number.
Returns
The value of the symbol plus or minus one.
Description
These
operators perform auto-increments or decrements on numeric
symbols. When the ++ is placed before a
symbol, it performs a pre-increment, where the value is
incremented and the result is the symbol's value + 1. When
++ is placed after a symbol, it performs a
post-increment. Here the result of the operation is the value of
the symbol prior to being incremented. The
-- operator works in the same way. These
operators only take symbols as arguments. It is not possible to
auto-increment or decrement an array element, list element, or
instance variable.
Examples
Gamma> a = 5;
5
Gamma> ++ a;
6
Gamma> a;
6
Gamma> a ++;
6
Gamma> a;
7
Gamma> a = 5;
5
Gamma> -- a;
4
Gamma> a;
4
Gamma> a --;
4
Gamma> a;
3
Gamma>
