[SOLVED] In a loop read 3 characters at a time

[Salis]

Ok I have a question. I have a string, say it's 26 characters long. How would I read 3 characters at a time then move on to the next 3. For an example:

 

$my_str = "ABCDEFGHIJKLMNOPQRTSUVWXYZ";

How would I read "ABC" then go to the next block "DEF" and so to the end?

[akitchin]

you need to find out how many sets of three characters you have, and loop through each using substr():

 

<?php
$my_str = 'ABCDEFGHIJKLMNOPQRTSUVWXYZ';
$sets = ceil(strlength($mystring) / 3);

for ($i = 0; $i <= $sets; ++$i)
{
  $this_set = substr($my_str, $i*3, 3);
  echo 'Set number '.$i+1.': '.$this_set.'<br />';
}
?>

 

you may have to fiddle with offsets and numbers, since i haven't tested, but that should work.

[effigy]

<pre>
<?php
$str = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
$start = 0;
while ($tmp_str = substr($str, $start, 3)) {
	echo $tmp_str, '<br>';
	$start += 3;
}
?>
</pre>

[Salis]

Thanks guys but I'm having a bit of trouble:

akitchin, I had to change 2 minor things strlength to strlen and ++$i to $i++ to get it to work, but for some reason I only get 1. ABC and that's it. By looking at your example shouldn't it return 9 blocks?

 

lol and effigy: I have no idea if this is coincidence, probably is, but as soon as I ran the script my server became unresponsive so I'm not sure if it works...

 

EDIT:

==============================

OK Yeah, I found the error and the server is back online!

I just had to change $mystring to $my_str it's almost all ways something simple..........

Thanks a bunch guys... BTY Where would I post a math question?

[effigy]

The code I posted works as is, and very quickly. Did you make any modifications? PHP version?

[akitchin]

effigy's code is far superior, don't bother even trying to modify mine.

[Salis]

Sorry, server is on line again and yeah this works great. I was able to work with both code but I'll take your advice and use effigy's example. In case you didn't see my edit, I need some (well a lot) of math help. Any one know where I should post a math question, if any where?

 

Thanks again, this really helps me a lot!

[effigy]

Try Miscellaneous. If it involves a lot of PHP, this forum should be fine.