iterating and changing value of an array using foreach and references - PHP 5.2.3

["Yashesh Bhatia" <yasheshb@xxxxxxxxx>]

Hi,

  Here's an interesting observation i noticed while using foreach to
iterate on arrays using
references for it's values.


-----------------------------------------------------------------------------------------------------------------
PHP version
$ php -v
PHP 5.2.3 (cli) (built: Jun  8 2007 14:31:21)
Copyright (c) 1997-2007 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2007 Zend Technologies
-----------------------------------------------------------------------------------------------------------------
Source code
<?php

// initialize array
$cat1 = array();
$cat1[15] = array('tid' => 15, 'ar_needed' => 'no');
$cat1[16] = array('tid' => 16, 'ar_needed' => 'no');
$cat1[17] = array('tid' => 17, 'ar_needed' => 'no');

// print it
print "\n\$cat1 = ";
print_r($cat1);
print "\n";

// iterate using foreach and reference
foreach ($cat1 as $k => &$v) {
  if ($k == 15) {
    $v['ar_needed'] = 'yes'; // dummy change
  }
}

// print array
print "\n\$cat1 = ";
print_r($cat1);
print "\n";

// reiterate
foreach ($cat1 as $k => $v) {
  print "\$k = $k\n";
  print "\$v = ";
  print_r($v);
  print "\n";
}
?>
-----------------------------------------------------------------------------------------------------------------
OUTPUT
$cat1 = Array
(
    [15] => Array
        (
            [tid] => 15
            [ar_needed] => no
        )
    [16] => Array
        (
            [tid] => 16
            [ar_needed] => no
        )
    [17] => Array
        (
            [tid] => 17
            [ar_needed] => no
        )
)

$cat1 = Array
(
    [15] => Array
        (
            [tid] => 15
            [ar_needed] => yes
        )
    [16] => Array
        (
            [tid] => 16
            [ar_needed] => no
        )
    [17] => Array
        (
            [tid] => 17
            [ar_needed] => no
        )
)

$k = 15
$v = Array
(
    [tid] => 15
    [ar_needed] => yes
)

$k = 16
$v = Array
(
    [tid] => 16
    [ar_needed] => no
)

$k = 17
$v = Array
(
    [tid] => 16
    [ar_needed] => no
)
-----------------------------------------------------------------------------------------------------------------

As seen in the above output all the print statements give expected
output except the last
set in the 2nd iteration
$k = 17
$v = Array
(
    [tid] => 16
    [ar_needed] => no
)

the $k looks fine but the $v is not correct for some reason. Any clue
what could be wrong
here ?. Also, in the 2nd iteration of the name of the variable is
changed from $v to $v1
it displays correctly
$k = 17
$v1 = Array
(
    [tid] => 17
    [ar_needed] => no
)


Thanks.

Yashesh Bhatia.

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