WordPress articles automatically add keywords and keyword SEO optimization_php skills

The keywords and web page descriptions of a website are related to the friendliness of the website to search engines. If you add them manually, it is obviously too troublesome. How can you make the WordPress blog automatically add keywords and web page descriptions for each article? The content of each article is different. How can we let WordPress automatically add article descriptions and keywords? Let’s take a look at how to automatically add article descriptions and keywords to WordPress.
Add the following code to your theme’s functions.php file. The functions of each code are analyzed as follows:

add_action ( 'wp_head', 'wp_keywords' ); // 添加关键字
add_action ( 'wp_head', 'wp_description' ); // 添加页面描述
 
function wp_keywords() {
 global $s, $post;
 $keywords = '';
 if (is_single ()) { //如果是文章页，关键词则是：标签+分类ID
 if (get_the_tags ( $post->ID )) {
  foreach ( get_the_tags ( $post->ID ) as $tag )
  $keywords .= $tag->name . ', ';
 }
 foreach ( get_the_category ( $post->ID ) as $category )
  $keywords .= $category->cat_name . ', ';
 $keywords = substr_replace ( $keywords, '', - 2 );
 } elseif (is_home ()) {
 $keywords = '我是主页关键词'; //主页关键词设置
 } elseif (is_tag ()) { //标签页关键词设置
 $keywords = single_tag_title ( '', false );
 } elseif (is_category ()) {//分类页关键词设置
 $keywords = single_cat_title ( '', false );
 } elseif (is_search ()) {//搜索页关键词设置
 $keywords = esc_html ( $s, 1 );
 } else {//默认页关键词设置
 $keywords = trim ( wp_title ( '', false ) );
 }
 if ($keywords) { //输出关键词
 echo "<meta name=\"keywords\" content=\"$keywords\" />\n";
 }
}

function wp_description() {
 global $s, $post;
 $description = '';
 $blog_name = get_bloginfo ( 'name' );
 if (is_singular ()) { //文章页如果存在描述字段，则显示描述，否则截取文章内容
 if (! empty ( $post->post_excerpt )) {
  $text = $post->post_excerpt;
 } else {
  $text = $post->post_content;
 }
 $description = trim ( str_replace ( array (
  "\r\n",
  "\r",
  "\n",
  "　",
  " " 
 ), " ", str_replace ( "\"", "'", strip_tags ( $text ) ) ) );
 if (! ($description))
  $description = $blog_name . "-" . trim ( wp_title ( '', false ) );
 } elseif (is_home ()) {//首页显示描述设置
 $description = $blog_name . "-" . get_bloginfo ( 'description' ) .'首页要显示的描述'; // 首頁要自己加
 } elseif (is_tag ()) {//标签页显示描述设置
 $description = $blog_name . "有关 '" . single_tag_title ( '', false ) . "' 的文章";
 } elseif (is_category ()) {//分类页显示描述设置
 $description = $blog_name . "有关 '" . single_cat_title ( '', false ) . "' 的文章";
 } elseif (is_archive ()) {//文档页显示描述设置
 $description = $blog_name . "在: '" . trim ( wp_title ( '', false ) ) . "' 的文章";
 } elseif (is_search ()) {//搜索页显示描述设置
 $description = $blog_name . ": '" . esc_html ( $s, 1 ) . "' 的搜索結果";
 } else {//默认其他页显示描述设置
 $description = $blog_name . "有关 '" . trim ( wp_title ( '', false ) ) . "' 的文章";
 }
 //输出描述
 $description = mb_substr ( $description, 0, 220, 'utf-8' ) . '..';
 echo "<meta name=\"description\" content=\"$description\" />\n";
}

Highlight keywords in search results:

function wps_highlight_results($text){
if(is_search()){
$sr = get_query_var('s');
$keys = explode(" ",$sr);
$text = preg_replace('/('.implode('|', $keys) .')/iu', '<strong>'.$sr.'</strong>', $text);
}
return $text;
}
add_filter('the_excerpt', 'wps_highlight_results');
add_filter('the_title', 'wps_highlight_results');

Use this snippet to highlight the search terms the_excerpt and the_title in your blog search results.