php如何实现搜索关键词高亮_php关键词高亮替换逻辑与样式实现

function highlightKeywords($text, $keywords) {
    if (empty($keywords)) return $text;
    // 转为数组，支持多个关键词
    $words = is_array($keywords) ? $keywords : [$keywords];
    foreach ($words as $word) {
        if (trim($word) === '') continue;
        // 使用正则表达式匹配关键词，添加<span>标签包裹
        $pattern = '/' . preg_quote($word, '/') . '/iu';  // i不区分大小写，u支持UTF-8
        $replace = '<span class="highlight">$0</span>';
        $text = preg_replace($pattern, $replace, $text);
    }
    return $text;
}

function highlightKeywordsSafe($text, $keywords) {
    $words = is_array($keywords) ? $keywords : [$keywords];
    foreach ($words as $word) {
        if (trim($word) === '') continue;
        $quoted = preg_quote($word, '/');
        // 只匹配非HTML标签内的文本（简单方式：排除<...>中的内容）
        $pattern = '/(?<=^|>)(' . $quoted . ')(?=<|$)/iu';
        $text = preg_replace($pattern, '<span class="highlight">$1</span>', $text);
    }
    return $text;
}

<style>
.highlight {
    background-color: #FFF275;
    padding: 2px 4px;
    border-radius: 3px;
    font-weight: bold;
}
</style>

$article = "这是一篇关于PHP编程的文章，介绍了PHP的基本语法和高亮实现方法。";
$keyword = $_GET['q'] ?? '';
echo highlightKeywords($article, $keyword);