Formatting question with semicolons

[barkster]

I have a string that can be any of the following want to make sure it is formatted correctly where if there is more than one entry they are separated by a semicolon and a space and the last entry does not have a semicolon.  I cannot figure out how to do this, right now I'm just doing this. So essentially it can either be 3digit alpha or 3-digit alpha plus semicolon and space? 

 

Formats Accepted

BBB

BBB; BBB

BBB; BBB; BBB; BBB

 

regex using now ^([A-Za-z; ])*$

[effigy]

<pre>
<?php

$tests = array(
	'BBB',
	'BBB; BBB',
	'BBB; BBB; BBB; BBB',
	'B;',
	';B',
	';;',
);

foreach ($tests as $test) {
	echo "$test => ";
	echo preg_match('/\A([^;]+;\s*)*[^;]+\z/', $test) ? 'OK' : 'Not OK' ;
	echo '<br>';
}

?>
</pre>

[barkster]

I forgot to mention it can only be 3-digit, so only 3-digit alpha or 3-digit alpha semicolon space

 

don't know how to make this as an or but need to combine these two or something simlilar

 

^([A-Za-z]{3})*

 

^([A-Za-z]{3};\s)*

[nrg_alpha]

Based off of Effigy's snippet, perhaps:

 

$tests = array(
	'BBB',
	'BBB; BBB',
	'BBB; BBB; BBB; BBB',
	'B;',
	';B',
	';;',
);

foreach ($tests as $test) {
    echo "$test => ";
    echo preg_match('#\A([a-z0-9]{3}(?:; )?)+\z#i', $test) ? 'OK' . "<br />\n" : 'Not OK' . "<br />\n" ;
}

 

Output:

BBB => OK
BBB; BBB => OK
BBB; BBB; BBB; BBB => OK
B; => Not OK
;B => Not OK
;; => Not OK

 

Is that what you are looking for?

[barkster]

yes that is it, thanks. It was the question mark that I didn't know how to use.  Optional instead of or.  Thanks!

[nrg_alpha]

I just realized that if it is only a format you are checking (in other words, you won't need to do any capturing at all), my initial brackets should be converted to non-capturing, much like the optional ;space part...

 

Pattern:

'#\A(?:[a-z0-9]{3}(?:; )?)+\z#i'