我试图计算每个博客帖子中的段落总数，但没有执行，因此没有返回任何内容。

How do you want to use this code?

当前在我的function.php 我使用以下代码在帖子中显示广告：

add_filter( \'the_content\', \'_some_func\' );

function _some_func( $content ) {

    $ad_code = "the ad code";

    if ( is_singular( \'post\' ) ) {
        return prefix_insert_after_paragraph( $ad_code, 12, $content );
    }

    return $content;
}

// Parent Function that makes the magic happen
function prefix_insert_after_paragraph( $insertion, $paragraph_id, $content ) {
    $closing_p = \'</p>\';
    $paragraphs = explode( $closing_p, $content );
    foreach ($paragraphs as $index => $paragraph) {

        if ( trim( $paragraph ) ) {
            $paragraphs[$index] .= $closing_p;
        }

        if ( $paragraph_id == $index + 1 ) {
            $paragraphs[$index] .= $insertion;
        }
    }

    return implode( \'\', $paragraphs );
}

现在，我想通过基于现在有许多段落的代码服务将其提升到下一个级别，如下所示：

add_filter( \'the_content\', \'_some_func\' );

function _some_func( $content ) {

    if( __check_paragraph_count_blog() > 15 )
        $ad_code = "the ad code";

    if ( is_singular( \'post\' ) ) {
        return prefix_insert_after_paragraph( $ad_code, 12, $content );
    }

    return $content;
}

所以，我试着写以下内容__check_paragraph_count_blog() 函数获取总段落数，以便我可以在上面的调用中使用它。

function __check_paragraph_count_blog() {
    global $post;
    if ( is_singular( \'post\' ) ) {
        $count = substr_count( $post->post_content, \'</p>\' );
        return $count;
    } else {
        return 0;
    }
}

我的__check_paragraph_count_blog() 功能：

它总是返回0，它认为</p> 内部标签<code> 和<pre> 标签也是__check_paragraph_count_blog() 功能，使其正常工作，这将是一个非常大的帮助。

add_filter( \'the_content\', \'_some_func\', 15 );

function _some_func( $content ) {

    if( __check_paragraph_count_blog( $content ) > 15 )
        $ad_code = "the ad code";
    else
        $ad_code = \'\';

    return prefix_insert_after_paragraph( $ad_code, 12, $content );

}


function __check_paragraph_count_blog( $content ) {
    global $post;
    if ( $post->post_type == \'post\' ) {
        $count = substr_count( $content, \'</p>\' );
        return $count;
    } else {
        return 0;
    }
}

add_action (\'wp\', \'wpse237301_check_paragraph_count_blog\');