在json中显示WP类别ID

Question

I made a page that shows some data in json format from a Wordpress database. Now I want show the category id of posts, but it shows all the ids before the object "ads"

My source:

<?php

header("Content-type: application/json");

include ('wp-load.php');


$loop = new WP_Query(array( 'post_status' => 'publish', 'post_type' => 'post'));
if($loop->have_posts()) : while($loop->have_posts()) : $loop->the_post();
    $posts[] = array(
        'id' => $post->ID,
        'post_title' => $post->post_title,
        'post_content' => $post->post_content,
        'guid' => $post->guid,

        'thumbnail' => (has_post_thumbnail() ? get_the_post_thumbnail_url() : ''),
        'cats' => the_category_ID(),

    );
endwhile; endif;
echo json_encode(array('ads' => $posts));

?>

Answer 1

It shows IDs before because of this line 'cats' => the_category_ID(),

What does this function do?

This function actually echos the category ID ( as it's argument is true by default ).

How to fix?

Pass false inside the_category_ID like this the_category_ID( false )

Corrected code

header("Content-type: application/json");

include ('wp-load.php');


$loop = new WP_Query(array( 'post_status' => 'publish', 'post_type' => 'post'));
if($loop->have_posts()) : while($loop->have_posts()) : $loop->the_post();
    $posts[] = array(
        'id' => $post->ID,
        'post_title' => $post->post_title,
        'post_content' => $post->post_content,
        'guid' => $post->guid,

        'thumbnail' => (has_post_thumbnail() ? get_the_post_thumbnail_url() : ''),
        'cats' => the_category_ID( false ),

    );
endwhile; endif;
echo json_encode(array('ads' => $posts));

Answer 2

if($loop->have_posts()) : while($loop->have_posts()) : 
    $loop->the_post();
    $posts[] = array(
        'id' => $post->ID,
        'post_title' => $post->post_title,
        'post_content' => $post->post_content,
        'guid' => $post->guid,

        'thumbnail' => (has_post_thumbnail() ? get_the_post_thumbnail_url() : ''),
        'cats' => the_category_ID(),
    );
    ob_clean();
endwhile; endif;

use ob clean