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Re: Doubt regarding an array of references...

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On 4/3/2012 7:39 AM, M. Strobel wrote:
>
> My 2¢:
>
> The problem with the counted for-loop is tedious writing, and off-by-one error.
>

No error if you remember what you're doing.  They can be tedious, but 
allow more control over the loop.  The real problem here is the indicies 
must be integers and sequential.

OTOH, foreach() loops process the elements in the order they were added 
to the array, which is not necessarily numeric order, i.e.

$a = array(3=>4, 2=>5, 1=>6);
foreach ($a as $v)
   echo "$v\n";

prints
4
5
6

Whereas
for ($i = 1; i < 4; i++)
   echo "$v\n";

prints
6
4
5

> The problem with the foreach-loop is: don't forget to use the key when you want to
> change values!
>
> This works:
>
> #--------------------------------
> strobel@s114-intel:~>  php -a
> Interactive shell
>
> php>  $a = array(1,2,3);
> php>  foreach ($a as $k=>$v) { $a[$k]++; }
> php>  var_dump($a);
> array(3) {
>    [0]=>
>    int(2)
>    [1]=>
>    int(3)
>    [2]=>
>    int(4)
> }
> php>  foreach ($a as $k=>$v) { $a[$k]*=4; }
> php>  var_dump($a);
> array(3) {
>    [0]=>
>    int(8)
>    [1]=>
>    int(12)
>    [2]=>
>    int(16)
> }
> php>
> #--------------------------
>
> I see references in PHP as "a can of worms", in PHP5 they are only necessary in very
> special cases.
>
> /Str.
>

References are very handy - and prevent the need for such gyrations as 
you're going through.

I find this much easier to understand:

$a = array(1,2,3);
foreach ($a as &$v) {
   $v++;
}


-- 
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex@attglobal.net
==================

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Thread

Doubt regarding an array of references... "Leonardo Azpurua" <leonardo@exmvps.org> - 2012-04-02 11:47 -0430
  Re: Doubt regarding an array of references... "Álvaro G. Vicario" <alvaro.NOSPAMTHANX@demogracia.com.invalid> - 2012-04-03 11:02 +0200
    Re: Doubt regarding an array of references... "M. Strobel" <sorry_no_mail_here@nowhere.dee> - 2012-04-03 13:39 +0200
      Re: Doubt regarding an array of references... Jerry Stuckle <jstucklex@attglobal.net> - 2012-04-03 08:03 -0400
        Re: Doubt regarding an array of references... "M. Strobel" <sorry_no_mail_here@nowhere.dee> - 2012-04-03 14:15 +0200
        Re: Doubt regarding an array of references... "M. Strobel" <sorry_no_mail_here@nowhere.dee> - 2012-04-04 10:48 +0200

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