Sort consecutive numbers differently

[bfears]

I have a small array of integers:
$foo = array(1,3,5,6,7,15,17,18,19,20);

CSV is great for the most part, but to clean the output up a bit, I need to implode() 3 or more consecutive numbers with a '-'.

Ideally, I'd like my output string to look something like "1,3,5-7,15,17-20".

Do I need to build an additional array to keep the consecutive values in? I've seen it done in perl, and it appears that they did just that, but I lack any real perl experience to fully grasp their example. Thanks.

[reagent]

a little rough, but try this
$arrNumbers = array(1,3,5,6,7,8,12,13,14,15,16,21);

$strRange = '';
for ($iIndex = 0; $iIndex < sizeof($arrNumbers); $iIndex++)
{
if ($arrNumbers[$iIndex] +1 == $arrNumbers[$iIndex + 1])
{
$strRange.= $arrNumbers[$iIndex].' - ';
while ($arrNumbers[$iIndex] +1 == $arrNumbers[$iIndex + 1])
{
$iIndex++;
}
$strRange.= $arrNumbers[$iIndex].', ';
}
else
{
$strRange.= $arrNumbers[$iIndex].', ';
}
}
print preg_replace('/,\s*$/i', '', $strRange);

you'll need to get rid of any duplicate numbers to make this function the way you'd want.

p.

[bfears]

Wonderful! Thank you. The while statement seems to be the piece I've been missing...as simple a concept as that may seem.

Let me ask you this -- is there any reason the $strRange = ''; needs to be there, or is that similar to C, where you protect it from grabbing whatever memory space it happens be have?

Brad

p. reagan wrote:

a little rough, but try this
$arrNumbers = array(1,3,5,6,7,8,12,13,14,15,16,21);

$strRange = '';
for ($iIndex = 0; $iIndex < sizeof($arrNumbers); $iIndex++)
{
if ($arrNumbers[$iIndex] +1 == $arrNumbers[$iIndex + 1])
{
$strRange.= $arrNumbers[$iIndex].' - ';
while ($arrNumbers[$iIndex] +1 == $arrNumbers[$iIndex + 1])
{
$iIndex++;
}
$strRange.= $arrNumbers[$iIndex].', ';
}
else
{
$strRange.= $arrNumbers[$iIndex].', ';
}
}
print preg_replace('/,\s*$/i', '', $strRange);

you'll need to get rid of any duplicate numbers to make this function the way you'd want.

p.