PHP - preg_match()

Question

This code prints "Got match" if the string can be matched in the /$reg/. Is is possible for me not just to match but display all the possible strings from that regular expression. Like for example my regular expression is "(a|b)*" possible strings are aaaa, abbb, bbbb, bbbaa, etc. I want to print all of those with the maximum length 5.

if(isset($_POST['calc'])){
$reg = $_POST['regex']; 
$str = $_POST['str'];

if (preg_match("/$reg/", $str)) 
{
    echo "Got match!";
}

else 
{
echo "String not valid";
}
}

?>

AndreKR · Accepted Answer · 2012-02-09 03:04:39Z

3

unset($matches);
if (preg_match_all("/$reg/", $str, $matches, PREG_PATTERN_ORDER)) 
{
    var_dump($matches[0]);
}

See the documentation.

answered Feb 9, 2012 at 3:04

AndreKR

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Comments

Phil · Accepted Answer · 2012-02-09 03:11:13Z

0

Use preg_match_all()

if (preg_match_all('/\b[ab]{1,5}\b/', $str, $matches)) {
    echo implode(', ', $matches[0]);
}

This finds all strings of sequential "a" or "b" characters up to a maximum length of 5.

edited Feb 9, 2012 at 3:11

answered Feb 9, 2012 at 3:04

Phil

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2 Comments

John Over a year ago

Thank you sir, can I ask a question? If this finds all strings of sequential "a" or "b" how come there is still an string in the parameters ($str). what string should I put there?

Phil Over a year ago

@John $str is the subject of the search

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