PHP Function: Word Filter

Feb 10, 2008 by CrunchBang

So, last night I was mainly experimenting with Whird, more specifically I was trying to build an internal search feature. This is something I’ve been putting off for long enough, and I’d really like to get it coded up. I didn’t finish it last night, but at least I’ve made a start.

Anyhow, during my experimentation I wrote this little PHP function for filtering words out of a string. Basically the function takes 2 strings as arguments before filtering words out of the first string based on words found in the second. I’ve posted it below for future reference:

function word_filter($string1,$string2){
    $string1 = trim($string1);
    $string1 = preg_replace('/s+/', ' ', $string1);
    $string1 = explode(" ",$string1);
    $wordcount = count($string1);
    $i = 0;
    while ($i < $wordcount) {
        $string = $string1[$i];
        if (strstr(strtolower($string2),strtolower($string))) {
            $string1[$i] = "";
        }
    $i++;
    }
$string1 = implode(" ",$string1);
return($string1);
}

Example usage

This is probably not the best example, but this:

$poem = <<<EOD
<p><em>GIVE me women, wine, and snuff <br />
Untill I cry out "hold, enough!" <br />
You may do so sans objection <br />
Till the day of resurrection: <br />
For, bless my beard, they aye shall be <br />
My beloved Trinity.</em></p>
EOD;

$common_words = 'and be but do for is it may me my not of the they there so was you';

echo word_filter($poem,$common_words);

Would output something like this:

GIVE women, wine, snuff
Untill cry out “hold, enough!”
sans objection
Till day resurrection:
For, bless beard, aye shall
beloved Trinity.

John Keats would be proud, not! Please feel free to optimise, or let me know if a one line equivalent already exists :)

Philip Newborough. Some Rights Reserved.
Licensed under a Creative Commons Attribution-Share Alike 2.0 UK: England & Wales License.