The -- operator is the
auto-decrement operator and is a common construct in modern
programming languages, including
C,
PHP,
VBScript,
Java and
JavaScript and
Perl. Basically its effect is to reduce the numerical value of a variable by one. It has a different effect depending on how it is used:
$y = 5;
$x = $y--;
# $y is 4, but $x is 5.
compare to the following:
$y = 5;
$x = --$y;
# now both $x and $y are 4.
Using the -- operator
after the variable causes the decrement to occur
after the value is returned. Using the operator
before has the reverse effect.
The -- operator is the obverse of the
++ operator, which was inspired by the "
newspeak" in
1984. Like
++, -- has slipped into
hacker and geek vocabulary to indicate a perceived decrease in the value of the
subject.
See also
++ and the nodes on
Perl,
C,
Java and
PHP and the
perlop manpage.
This has been a nodeshell rescue. Thanks to ariels for correcting a moderately bad braino on my part.