如何从多维数组内的WP_Query对象中获取post_content、ID等文章数据

你当前的代码存在可优化点：循环遍历时你将整个WP_Query对象存入了$master数组，实际使用只需要存储当前文章的相关字段即可，既节省内存也方便后续调用。两种实现方案如下：

方案1：优化存储逻辑（推荐） #

在遍历文章的阶段直接提取所需字段存入数组，后续调用更简单：

global $post;

$args = array(
    'post_type' => 'history',
    'order'     => 'ASC'
);

$master = [];
    
$post_query = new WP_Query($args);

if ($post_query->have_posts() ) {
            
    while ($post_query->have_posts()) {
        $post_query->the_post();
        
        /* 获取文章日期 */
        $year = get_the_date( 'Y' );
        $mon = get_the_date( 'M' );

        // 直接提取所需字段存入数组
        $post_data = [
            'post_id'       => get_the_ID(), // 文章ID
            'post_content'  => get_the_content(), // 文章内容
            'pagename'      => $post->post_name, // pagename对应文章的slug字段
            'categories'    => get_the_category(), // 文章分类对象数组
        ];
            
        $master[$year][$mon][] = $post_data;
        
    }
    
    foreach ($master as $masterkey => $mastervalue) {
        echo "<p>";
        echo "年份: ".  $masterkey . "<br>";
        foreach($mastervalue as $mon => $post_list) {
            echo "月份: " . $mon . "<br>";
            // 遍历当月所有文章输出字段
            foreach($post_list as $post_item) {
                echo "文章ID：" . $post_item['post_id'] . "<br>";
                echo "文章别名：" . $post_item['pagename'] . "<br>";
                echo "文章内容：" . $post_item['post_content'] . "<br>";
                // 输出分类名称
                echo "文章分类：";
                foreach($post_item['categories'] as $cat) {
                    echo $cat->name . ' ';
                }
                echo "<br><hr>";
            }
        }
        echo "</p>";
    }
    
}
wp_reset_postdata();

方案2：从现有存储的WP_Query对象直接提取 #

如果你不想修改存储逻辑，直接从当前$value中存储的WP_Query对象提取字段的代码如下：

foreach($mastervalue as $key => $value) {
    echo "key: " . $key . "<br>";
    // WP_Query的posts属性存储了所有查询到的文章对象
    foreach($value->posts as $post_item) {
        echo "文章ID：" . $post_item->ID . "<br>";
        echo "文章内容：" . $post_item->post_content . "<br>";
        echo "文章别名：" . $post_item->post_name . "<br>";
        // 传入文章ID获取对应分类
        $categories = get_the_category($post_item->ID);
        echo "文章分类：";
        foreach($categories as $cat) {
            echo $cat->name . ' ';
        }
        echo "<br>";
    }                      
}

内容的提问来源于stack exchange，提问作者la_petite_kozel