note 92752 modified in function.implode by danbrown
| From: | danbrown@php.net | Date: | Fri, 07 Aug 2009 14:45:38 +0000 |
| Subject: | note 92752 modified in function.implode by danbrown | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-159188@lists.php.net to get a copy of this message | ||
As "john" pointed out on 2004 Apr 26, implode does not always work in a way that could be
considered intuitive.
You may need to sort your elements with ksort, or write a longer routine to fill in any
"gaps". See this example:
<?php
$a = array(1=>'one', 7=>'seven', 5=>'five');
$b = implode (',', $a);
ksort ($a);
$c = implode (',', $a);
$highest = max(array_keys($a));
for ($i = 0; $i <= $highest; ++$i):
if (! isset($a[$i])):
$a[$i] = '';
endif;
endfor;
ksort ($a);
$d = implode (',', $a);
print "\$b = '$b'<br>\n";
print "\$c = '$c'<br>\n";
print "\$d = '$d'<br>\n";
/*
output:
$b = 'one,seven,five'
$c = 'one,five,seven'
$d = ',one,,,,five,,seven'
*/
?>
Or, as a function:
<?php
function ensure (&$a, $filler = '') {
// given: array $a with numerical keys
// return: $a with keys sorted numerically and any gaps filled-in
$highest = max(array_keys($a));
for ($i = 0; $i <= $highest; ++$i):
if (! isset($a[$i])):
$a[$i] = $filler;
endif;
endfor;
ksort ($a);
} // end function ensure
// usage:
// ensure($foo);
// ensure($bar, 0);
?>
--was--
As "john" pointed out on 2004 Apr 26, implode does not always work in a way that could be
considered intuitive.
You may need to sort your elements with ksort, or write a longer routine to fill in any
"gaps". See this example:
<?php
$a = array(1=>'one', 7=>'seven', 5=>'five');
$b = implode (',', $a);
ksort ($a);
$c = implode (',', $a);
$highest = max(array_keys($a));
for ($i = 0; $i <= $highest; ++$i):
if (! isset($a[$i])):
$a[$i] = '';
endif;
endfor;
ksort ($a);
$d = implode (',', $a);
print "\$b = '$b'<br>\n";
print "\$c = '$c'<br>\n";
print "\$d = '$d'<br>\n";
/*
output:
$b = 'one,seven,five'
$c = 'one,five,seven'
$d = ',one,,,,five,,seven'
*/
?>
http://php.net/manual/en/function.implode.php