header("Content-Type:text/html;charset=utf-8"); //Set encoding
$linkdatas=array(
array('front-end development', 'http://https://'),
array('front end design', 'https://'),
array('Web frontend', 'https://'),
array('front-end blog', 'https://'),
);
echo "Before replacement<br/>";
echo $str='Web front-end development - Focus on website front-end design and Web user experience. Front-end development, focusing on web front-end development, paying attention to web user experience, and paying attention to the latest and best front-end design resources and front-end development technology at home and abroad';
echo "<br/>After replacement<br/>";
echo $str=keylinks($str,2);
/**
* Related keyword replacement
* @param txt $string Original string
* @param replacenum $int Number of replacements
* @return string Return string
*/
function keylinks($txt, $replacenum = '') {
global $linkdatas;
if ($linkdatas) {
$word = $replacement = array();
foreach ($linkdatas as $v) {
$word1[] = '/(?!(<a.*?))' . preg_quote($v[0], '/') . '(?!.*<\/a>)/s';
$word2[] = $v[0];
$replacement[] = '<a href="' . $v[1] . '" target="_blank" class="keylink">' . $v[0] . '</a>';
}
if ($replacenum != '') {
$txt = preg_replace($word1, $replacement, $txt, $replacenum);
} else {
$txt = str_replace($word2, $replacement, $txt);
}
}
return $txt;
}