Highlight keywords in a paragraph

Question

I need to highlight a keyword in a paragraph, as google does in its search results. Let\'s assume that I have a MySQL db with blog posts. When a user searches for a certain

Answer 1

I found this post when doing a search for how to highlight keyword search results. My requirements were:

• Must be whole words
• Must work for more than one keyword
• Must be PHP only

I am fetching my data from a MySQL database, which doesn't contain elements, by design of the form which stores the data.

Here is the code I found most useful:

$keywords = array("fox","jump","quick");
$string = "The quick brown fox jumps over the lazy dog";
$test = "The quick brown fox jumps over the lazy dog"; // used to compare values at the end.

if(isset($keywords)) // For keyword search this will highlight all keywords in the results.
    {
    foreach($keywords as $word)
        {
        $pattern = "/\b".$word."\b/i";
        $string = preg_replace($pattern,"<span class=\"highlight\">".$word."</span>", $string);
        }
    }
 // We must compare the original string to the string altered in the loop to avoid having a string printed with no matches.
if($string === $test)
    {
    echo "No match";
    }
else
    {
    echo $string;
    }

Output:

The <span class="highlight">quick</span> brown <span class="highlight">fox</span> jumps over the lazy dog.

I hope this helps someone.