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Posted by JDS on 10/02/56 11:28
On Wed, 05 Oct 2005 11:26:52 +0200, Pugi! wrote:
> Can anyone help me understand this or see the logic in it ?
I know others are explaining it already, but here is my go.
++ increments an integer variable by one.
Whenever ++ is tacked onto a variable, the variable is incremented by one.
It doesn't matter if the variable is being passed into a function, is
being assigned to someting else, is in a for() loop, or is by itself.
++ can come *before* or *after* the variable, like this:
$i++
or this:
++$i
If ++ comes *before* the variable, then the statement on that line FIRST
increments the variable, and then uses that incremented value in the rest
of the statement.
If ++ comes *after* the variable, then the statement on that line first
uses the CURRENT value of the variable, and then increments the variable
at the end of the statement.
For example:
{
$a = 1;
$b = 2;
$c = $a + $b++;
}
// $c will be set to 3 and $b will be incremented to 3
This is different from this example:
{
$a = 1;
$b = 2;
$c = $a + ++$b;
}
// $b is incremented to 3 and then $c is set to 4
To use ++ unambiguously, always put it on a line by itself:
{
$a = 1;
$b = 2;
$c = $a + $b;
$b++;
}
does the same thing as
{
$a = 1;
$b = 2;
$c = $a + $b;
++$b;
}
That example is much less ambiguous than either of the first two.
later...
--
JDS | jeffrey@example.invalid
| http://www.newtnotes.com
DJMBS | http://newtnotes.com/doctor-jeff-master-brainsurgeon/
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